JP4454008B2

JP4454008B2 - Multi-wavelength batch wavelength converter and multi-wavelength batch wavelength conversion method

Info

Publication number: JP4454008B2
Application number: JP2003346777A
Authority: JP
Inventors: 悦史山崎; 篤高田; 山涌　　純; 敏夫盛岡; 雅生遊部; 修忠永
Original assignee: Nippon Telegraph and Telephone Corp
Current assignee: Nippon Telegraph and Telephone Corp
Priority date: 2003-10-06
Filing date: 2003-10-06
Publication date: 2010-04-21
Anticipated expiration: 2023-10-06
Also published as: JP2005114897A

Description

本発明は、波長分割多重技術を基盤とする光ネットワークにおける光ノード等において用いられる波長変換器及び波長変換方法に関する。 The present invention relates to a wavelength converter and a wavelength conversion method used in an optical node or the like in an optical network based on wavelength division multiplexing technology.

波長変換法としては、（１）変換において光位相情報を保持でき、（２）信号変調速度に依存せず、（３）多波長入力信号光を一括して変換可能である、などの長所を有する光非線形媒質を利用したパラメトリック波長変換法が活発に研究されている（非特許文献１，２，３参照）。 The wavelength conversion method has the following advantages: (1) optical phase information can be retained in the conversion, (2) independent of the signal modulation speed, and (3) multi-wavelength input signal light can be converted in a batch. A parametric wavelength conversion method using an optical nonlinear medium is actively researched (see Non-Patent Documents 1, 2, and 3).

パラメトリック波長変換法としては、光ファイバ、光半導体増幅器などにおける三次光非線形効果を利用する方法と、光非線形結晶などにおける二次光非線形効果を利用する方法がある。後者は、変換効率が高い、コンパクト、集積化の可能性、多波長入力信号光間のクロストークが小さいなどの長所を有しており、有望な方法である（非特許文献４，５参照）。 As the parametric wavelength conversion method, there are a method using a third-order optical nonlinear effect in an optical fiber, an optical semiconductor amplifier, and the like, and a method using a second-order optical nonlinear effect in an optical nonlinear crystal or the like. The latter has advantages such as high conversion efficiency, compactness, possibility of integration, and small crosstalk between multi-wavelength input signal lights, and is a promising method (see Non-Patent Documents 4 and 5). .

二次光非線形効果を利用した波長変換においては、入力される信号光と励起光との和周波光発生／差周波光発生過程を利用する。通常、信号光や励起光の光周波数帯と比較して、それらによって発生する和周波光の光周波数帯は、光周波数が２倍程度異なるために、両帯域における光の位相速度の相違は大きい。このために、両帯域の光同士の有効な相互作用距離は通信波長帯域（１．５μｍ帯）においては数十μｍ程度と非常に短くなり、高効率な変換ができない。差周波光発生過程においても同様である。 In wavelength conversion using the secondary light nonlinear effect, a sum frequency light generation / difference frequency light generation process of input signal light and excitation light is used. Usually, compared with the optical frequency band of signal light and pumping light, the optical frequency band of the sum frequency light generated by them differs by about twice as much as the optical frequency, so the difference in the phase velocity of light in both bands is large. . For this reason, the effective interaction distance between the light beams in both bands becomes as short as several tens of μm in the communication wavelength band (1.5 μm band), and high-efficiency conversion cannot be performed. The same applies to the difference frequency light generation process.

そこで、一般に、二次光非線形効果を用いる場合には、有効な相互作用距離を拡大するために、周期的に二次光非線形結晶の光学軸を反転する擬似位相整合（ＱＰＭ）技術が利用される。これによって、二次光非線形媒質における和周波光／差周波光発生の発生効率が向上し、高い変換効率が実現される。
S. J. B. Yoo, "Wavelength conversion technologies for WDM network applications," J. Lightwave Technol., Vol.14, No.6, 1996, pp.955-966 K. Inoue, "Tunable and selective wavelength conversion using fiber four-wave mixing with two pumps," IEEE Photonics Technology Letters, Vol.6, No.12, 1994 M. H. Chou, I. Brener, M. M. Fejer, E. E. Chaban, and S. B. Christman, "1.5μm-band wavelength conversion based on cascaded second-order nonlinearity in LiNbO3 waveguides," IEEE Photonics Technol. Letters, Vol.11, No.6, June 1999 M. Asobe, O. Tadanaga, T. Yamagawa, H. Itoh, and H. Suzuki, "Reducing photorefractive effect in periodically poled ZnO- and MgO- doped LiNbO3 wavelength converters," Applied Physics Letters, Vol.78, No.21, May 2001 川口竜生、吉野隆文、今枝美能留、水内公典、北岡康夫、山本和久「貼合せ・リッジ構造ＬＮ光導波路を用いたＱＰＭ−ＳＨＧデバイス」電子情報通信学会信学技報、ＬＱＥ２００２−８、２００２、ｐ．２９ Therefore, in general, when using the second-order optical nonlinear effect, a quasi-phase matching (QPM) technique that periodically inverts the optical axis of the second-order nonlinear optical crystal is used in order to increase the effective interaction distance. The As a result, the generation efficiency of sum frequency light / difference frequency light generation in the secondary light nonlinear medium is improved, and high conversion efficiency is realized.
SJB Yoo, "Wavelength conversion technologies for WDM network applications," J. Lightwave Technol., Vol.14, No.6, 1996, pp.955-966 K. Inoue, "Tunable and selective wavelength conversion using fiber four-wave mixing with two pumps," IEEE Photonics Technology Letters, Vol. 6, No. 12, 1994 MH Chou, I. Brener, MM Fejer, EE Chaban, and SB Christman, "1.5μm-band wavelength conversion based on cascaded second-order nonlinearity in LiNbO3 waveguides," IEEE Photonics Technol. Letters, Vol. 11, No. 6, June 1999 M. Asobe, O. Tadanaga, T. Yamagawa, H. Itoh, and H. Suzuki, "Reducing photorefractive effect in periodically poled ZnO- and MgO- doped LiNbO3 wavelength converters," Applied Physics Letters, Vol. 78, No. 21 , May 2001 Tatsuo Kawaguchi, Takafumi Yoshino, Minoru Imae, Kiminori Mizuuchi, Yasuo Kitaoka, Kazuhisa Yamamoto "QPM-SHG Device Using Bonded Ridge Structure LN Optical Waveguide" IEICE Technical Report, LQE2002-8, 2002 , P. 29

擬似位相整合技術を用いた和周波光発生においては、二次光非線形結晶の光学軸の反転周期によって一意に決定される光周波数２ν₀の和周波光が発生する場合にのみ、有効な相互作用距離が拡大し、高効率な和周波光発生が可能である。差周波光発生においても同様であり、光周波数２ν₀の光と光周波数ν₀付近の光との差周波光発生の場合においてのみ、高効率な差周波光発生が可能になる。 In sum frequency light generation using a quasi-phase matching technique, an effective interaction is effective only when sum frequency light having an optical frequency of 2ν ₀ uniquely determined by the inversion period of the optical axis of the secondary optical nonlinear crystal is generated. The distance is increased, and high-efficiency sum frequency light generation is possible. The same applies to the generation of the difference frequency light. Only when the difference frequency light is generated between the light having the optical frequency 2ν _{0 and} the light in the vicinity of the optical frequency ν ₀ , the highly efficient difference frequency light can be generated.

このような条件で、変換先波長を任意に制御可能な任意波長変換を実現する方法として、２つの励起光を用いる方法が提案されている。そこでは、光周波数ν_s＝２ν₀−ν_P1の信号光に対して、光周波数ν_P1の第１の励起光を用いることで、光周波数２ν₀の和周波光を発生させ、さらに、その和周波光と光周波数ν_P2の第２の励起光との差周波光発生によって２ν₀−ν_P2＝ν_cに信号光を変換する。従って、高効率な和周波光発生／差周波光発生が可能であり、励起光の光周波数ν_P1及びν_P2を制御することで、高い変換効率を維持したまま任意の光周波数の入力光を任意の光周波数の出力光に変換可能である。 Under such conditions, a method using two excitation lights has been proposed as a method for realizing arbitrary wavelength conversion in which the conversion destination wavelength can be arbitrarily controlled. In this case, the first pumping light having the optical frequency ν _P1 is used for the signal light having the optical frequency ν _s = 2ν ₀ −ν _P1 to generate the sum frequency light having the optical frequency 2ν _0. The signal light is converted into 2ν ₀ −ν _P2 = ν _c by the generation of the difference frequency light between the sum frequency light and the second excitation light having the optical frequency ν _P2 . Therefore, high-efficiency sum-frequency light generation / difference-frequency light generation is possible. By controlling the optical frequencies ν _P1 and ν _P2 of the pumping light, it is possible to input light of any optical frequency while maintaining high conversion efficiency. It can be converted into output light of any optical frequency.

この方法を入力信号光が多波長光である場合に適用しようとすると、複数の和周波光を発生させる必要がある。しかし、ＱＰＭ二次光非線形媒質では１つの光周波数２ν₀のみに対して高効率な和周波光発生が可能であるために、多波長入力信号光の一括任意波長変換が不可能であるという課題があった。 If this method is applied when the input signal light is multi-wavelength light, it is necessary to generate a plurality of sum frequency lights. However, since the QPM secondary optical nonlinear medium can generate high-efficiency sum frequency light for only one optical frequency 2ν _0, it is impossible to perform batch arbitrary wavelength conversion of multi-wavelength input signal light. was there.

本発明の目的は、任意の波長（光周波数）の多波長入力信号光を一括して任意の波長（光周波数）の多波長変換光に変換可能な多波長一括波長変換器を提供することにある。 An object of the present invention is to provide a multi-wavelength batch wavelength converter capable of collectively converting multi-wavelength input signal light having an arbitrary wavelength (optical frequency) into multi-wavelength converted light having an arbitrary wavelength (optical frequency). is there.

前記目的を達成するため、本発明では、次のような特徴的な構成を採用している。 In order to achieve the object, the present invention adopts the following characteristic configuration.

即ち、第１の発明では、図１に示すように、２以上の整数Ｎに対して、任意の光周波数２ν₁−ν_P1，２ν₂−ν_P1，……２ν_N−ν_P1の多波長入力信号光をそれぞれ任意の光周波数２ν₁−ν_P2，２ν₂−ν_P2，……２ν_N−ν_P2の多波長変換光に変換する多波長一括波長変換器であって、光周波数ν_P1の第１の励起光源１１と、光周波数ν_P2の第２の励起光源１２と、二次高調波光発生効率が極大となる光周波数（ＱＰＭ光周波数）としてν₁，ν₂，……ν_Nを含む二次光非線形媒質１３と、多波長入力信号光と前記第１の励起光源からの出力光と前記第２の励起光源からの出力光とを合波し、前記二次光非線形媒質へ入力する合波手段１４とを有する多波長一括波長変換器及びその多波長一括波長変換方法をもって解決手段とする。 That is, in the first invention , as shown in FIG. 1, for an integer N of 2 or more, multiple wavelengths of arbitrary optical frequencies 2ν ₁ −ν _P1 , 2ν ₂ −ν _P1 , ... 2ν _N −ν _P1 . A multi-wavelength batch wavelength converter that converts input signal light into multi-wavelength converted light of arbitrary optical frequencies 2ν ₁ −ν _P2 , 2ν ₂ −ν _P2 ,... 2ν _N −ν _P2 , and has an optical frequency ν _P1. a first pumping light source 11, a second pumping light source 12 of the optical frequency [nu _P2, [nu ₁ as second harmonic light generation efficiency becomes maximum optical frequency (QPM optical frequency), ν _2, ...... ν _N , The multi-wavelength input signal light, the output light from the first excitation light source, and the output light from the second excitation light source are combined into the secondary optical nonlinear medium. The multi-wavelength batch wavelength converter having the multiplexing means 14 for input and the multi-wavelength batch wavelength conversion method are used as the solution means.

第１の発明の構成では、和周波光発生過程と差周波光発生過程とを同一の二次光非線形媒質１３で行う。即ち、二次光非線形媒質１３に入力された光周波数２ν₁−ν_P1，２ν₂−ν_P1，……２ν_N−ν_P1の多波長入力信号光と光周波数ν_P1の第１の励起光との間で和周波光発生過程により光周波数２ν₁，２ν₂，……２ν_Nの和周波光が発生し、該和周波光と同じく二次光非線形媒質１３に入力された光周波数ν_P2の第２の励起光との間で差周波光発生過程により２ν₁−ν_P2，２ν₂−ν_P2，……２ν_N−ν_P2の多波長変換光を得る。 In the configuration of the first invention , the sum frequency light generation process and the difference frequency light generation process are performed by the same secondary light nonlinear medium 13. That is, the optical wavelengths 2ν ₁ −ν _P1 , 2ν ₂ −ν _P1 ,... 2ν _N −ν _P1 input to the secondary nonlinear optical medium 13 and the first excitation light having the optical frequency ν _P1 . 2ν ₁ , 2ν ₂ ,... 2ν _N is generated by the sum frequency light generation process between the optical frequency ν _P2 and the optical frequency ν _P2 input to the secondary optical nonlinear medium 13 in the same manner as the sum frequency light. Multi-wavelength converted light of 2ν ₁ −ν _P2 , 2ν ₂ −ν _P2 ,... 2ν _N −ν _P2 is obtained by the difference frequency light generation process with the second pumping light.

また、第２の発明では、図２に示すように、２以上の整数Ｎに対して、任意の光周波数２ν₁−ν_P1，２ν₂−ν_P1，……２ν_N−ν_P1の多波長入力信号光をそれぞれ任意の光周波数２ν₁−ν_P2，２ν₂−ν_P2，……２ν_N−ν_P2の多波長変換光に変換する多波長一括波長変換器であって、光周波数ν_P1の第１の励起光源１１と、光周波数ν_P2の第２の励起光源１２と、二次高調波光発生効率が極大となる光周波数としてν₁，ν₂，……ν_Nを含む第１及び第２の二次光非線形媒質２１及び２２と、多波長入力信号光と前記第１の励起光源からの出力光とを合波し、前記第１の二次光非線形媒質へ入力する第１の合波手段２３と、前記第１の二次光非線形媒質からの出力光と前記第２の励起光源からの出力光とを合波し、前記第２の二次光非線形媒質へ入力する第２の合波手段２４とを有する多波長一括波長変換器及びその多波長一括波長変換方法をもって解決手段とする。 Further, in the second invention , as shown in FIG. 2, for an integer N of 2 or more, multiple wavelengths of arbitrary optical frequencies 2ν ₁ −ν _P1 , 2ν ₂ −ν _P1 ,... 2ν _N −ν _P1 A multi-wavelength batch wavelength converter that converts input signal light into multi-wavelength converted light of arbitrary optical frequencies 2ν ₁ −ν _P2 , 2ν ₂ −ν _P2 ,... 2ν _N −ν _P2 , and has an optical frequency ν _P1. a first pumping light source 11, a second pumping light source 12 of the optical frequency [nu _P2, ₁ [nu as an optical frequency second harmonic light generation efficiency becomes maximum, [nu _2, the first and the ...... ν _N First second-order nonlinear optical media 21 and 22, multi-wavelength input signal light and output light from the first pumping light source are combined and input to the first second-order nonlinear optical medium. The multiplexing means 23, the output light from the first secondary optical nonlinear medium, and the output light from the second pumping light source are multiplexed, and the second secondary optical nonlinear medium is combined. The multi-wavelength collective wavelength converter having the second combining means 24 for inputting to the quality and the multi-wavelength collective wavelength conversion method are used as the solving means.

第２の発明の構成では、和周波光発生過程と差周波光発生過程とを、同一のＱＰＭ光周波数を有する２つの別々の二次光非線形媒質２１，２２で行う。即ち、前段の二次光非線形媒質２１には多波長入力信号光と第１の励起光が入力され、和周波光発生過程により和周波光が発生し、後段の二次光非線形媒質２２には該和周波光と第２の励起光が入力され、差周波光発生過程により多波長変換光を得る。 In the configuration of the second invention , the sum frequency light generation process and the difference frequency light generation process are performed by two separate secondary optical nonlinear media 21 and 22 having the same QPM optical frequency. That is, multi-wavelength input signal light and first excitation light are input to the secondary optical nonlinear medium 21 at the front stage, and sum frequency light is generated by the process of generating the sum frequency light, and the secondary optical nonlinear medium 22 at the rear stage is generated. The sum frequency light and the second excitation light are input, and multi-wavelength converted light is obtained by the difference frequency light generation process.

ところで、第１及び第２の発明の構成では、実際には、最終段から多波長変換光とともに多波長入力信号光、第１、第２の励起光及び和周波光が出力される。光ネットワークに用いる波長変換器では、出力光に励起光や入力信号光が混入しないようにすることが重要であるため、波長可変バンドパスフィルタ（ＢＰＦ）などの波長可変フィルタを利用して変換光のみを出力するようにする必要がある。 By the way, in the configurations of the first and second aspects of the invention , the multi-wavelength input signal light, the first and second excitation lights, and the sum frequency light are actually output from the final stage together with the multi-wavelength converted light. In a wavelength converter used in an optical network, it is important to prevent excitation light and input signal light from being mixed into output light. Therefore, converted light using a wavelength variable filter such as a wavelength variable bandpass filter (BPF) is used. Only need to output.

この点を考慮し、第３の発明では、図３に示すように、第２の発明において、前記第１の二次光非線形媒質２１と第２の合波手段２４との間に、光周波数２ν₁，２ν₂，……２ν_Nの光のみを透過する光フィルタ３１を設けた多波長一括波長変換器及びその多波長一括波長変換方法をもって解決手段とする。 Considering this point, in the third invention , as shown in FIG. 3, in the second invention , an optical frequency is provided between the first secondary optical nonlinear medium 21 and the second multiplexing means 24. 2ν ₁ , 2ν ₂ ,... A multi-wavelength collective wavelength converter provided with an optical filter 31 that transmits only 2ν _N light and a multi-wavelength collective wavelength conversion method are used as a solution.

第３の発明の構成では、前段の二次光非線形媒質２１の後に、和周波光の波長帯域付近（例えば７８０ｎｍ付近）の光を透過させ、入力信号光や励起光の波長帯域（例えば１５５０ｎｍ帯域）の光を遮断する波長特性を有するダイクロイックミラーなどの光フィルタ３１を用いることで、後段の二次光非線形媒質２２には和周波光及び第２の励起光のみを入力することができる。入力信号光及び第１の励起光が光フィルタ３１によって遮断され、変換光に混入しないことがメリットとして挙げられる。但し、第２の励起光及び和周波光は変換光に混入するため、第１及び第２の発明の構成と同様、後段の二次光非線形媒質２２の後に波長可変フィルタを設けて遮断する必要がある。 In the configuration of the third invention , light in the vicinity of the wavelength band of the sum frequency light (for example, near 780 nm) is transmitted after the secondary optical nonlinear medium 21 in the previous stage, and the wavelength band of the input signal light and the excitation light (for example, 1550 nm band). By using the optical filter 31 such as a dichroic mirror having a wavelength characteristic for blocking the light of (), only the sum frequency light and the second excitation light can be input to the secondary optical nonlinear medium 22 in the subsequent stage. An advantage is that the input signal light and the first excitation light are blocked by the optical filter 31 and are not mixed into the converted light. However, since the second excitation light and the sum frequency light are mixed in the converted light, it is necessary to provide a wavelength tunable filter after the second-order nonlinear optical medium 22 and block it, as in the configurations of the first and second inventions. There is.

また、第４の発明（但し、特許請求の範囲には含まれない。）では、図４に示すように、２以上の整数Ｎに対して、任意の光周波数２ν₁−ν_P1，２ν₂−ν_P1，……２ν_N−ν_P1の多波長入力信号光をそれぞれ任意の光周波数２ν₁−ν_P2，２ν₂−ν_P2，……２ν_N−ν_P2の多波長変換光に変換する多波長一括波長変換器であって、光周波数ν_P1の第１の励起光源１１と、光周波数ν_P2の第２の励起光源１２と、二次高調波光発生効率が極大となる光周波数としてν₁，ν₂，……ν_Nを含む二次光非線形媒質１３と、多波長入力信号光と前記第１の励起光源からの出力光とを合波し、前記二次光非線形媒質へ入力する第１の合波手段４１と、前記二次光非線形媒質からの出力光を前記第２の励起光源からの出力光と合波し、前記二次光非線形媒質に再び入力する第２の合波手段４２とを有する多波長一括波長変換器及びその多波長一括波長変換方法をもって解決手段とする。 In the fourth invention (but not included in the scope of claims) , as shown in FIG. 4, for an integer N of 2 or more, an arbitrary optical frequency 2ν ₁ −ν _P1 , 2ν _2. −ν _P1 ............ 2ν _N −ν _P1 multi-wavelength input signal light is converted into multi-wavelength converted light of any optical frequency 2ν ₁ −ν _P2 , 2ν ₂ −ν _P2 ,… 2ν _N −ν _P2 A multi-wavelength batch wavelength converter, a first pumping light source 11 having an optical frequency ν _P1, a second pumping light source 12 having an optical frequency ν _P2 , and an optical frequency at which the second harmonic light generation efficiency is maximized ν ₁ , ν ₂ ,..., Ν _N containing the secondary optical nonlinear medium 13, the multi-wavelength input signal light and the output light from the first pumping light source are combined and input to the secondary optical nonlinear medium. First light combining means 41 and output light from the second-order nonlinear light medium are combined with output light from the second excitation light source, and the second-order light nonlinear medium The multi-wavelength collective wavelength converter having the second combining means 42 to be input again and the multi-wavelength collective wavelength conversion method are used as the solving means.

第４の発明の構成では、第２の発明の構成において前段／後段の二次光非線形媒質での和周波／差周波光発生過程を、それぞれ、１つの二次光非線形媒質１３の往路／復路を用いて行う。即ち、二次光非線形媒質１３に多波長入力信号光と第１の励起光が入力され、和周波光発生過程により和周波光が発生し、二次光非線形媒質１３から出力され、該和周波光と第２の励起光が二次光非線形媒質１３に再び入力され、差周波光発生過程により多波長変換光を得る。 In the configuration of the fourth aspect of the invention , the sum frequency / difference frequency light generation process in the secondary optical nonlinear medium at the front stage / rear stage in the configuration of the second invention is changed to the forward / return path of one secondary optical nonlinear medium 13, respectively. To do. That is, the multi-wavelength input signal light and the first excitation light are input to the secondary optical nonlinear medium 13, sum frequency light is generated by the sum frequency light generation process, and is output from the secondary optical nonlinear medium 13. The light and the second excitation light are input again to the secondary light nonlinear medium 13, and multi-wavelength converted light is obtained by the difference frequency light generation process.

また、第４の発明の構成では、第１及び第２の発明の構成と同様、最終的に出力される多波長変換光には多波長入力信号光、第１、第２の励起光及び和周波光が混入しているため、第１の合波手段４１の前段に、波長可変フィルタを設けて変換光のみを出力するようにする必要がある。 Further, in the configuration of the fourth aspect of the invention, similar to that of the first and second aspects of the invention, the multi-wavelength converted light to be finally output multi-wavelength input signal light, first, second excitation light and the sum Since the frequency light is mixed, it is necessary to provide a wavelength tunable filter before the first multiplexing means 41 so as to output only the converted light.

この点を考慮し、第５の発明（但し、特許請求の範囲には含まれない。）では、図４に示すように、第４の発明において、前記二次光非線形媒質からの出力光のうち光周波数２ν₁，２ν₂，……２ν_Nの光のみを第２の励起光源からの出力光と合波し、前記二次光非線形媒質に再び入力する第２の合波手段４２’を有する多波長一括波長変換器及びその多波長一括波長変換方法をもって解決手段とする。 In consideration of this point, in the fifth invention (but not included in the scope of claims) , as shown in FIG. 4, in the fourth invention , the output light from the secondary optical nonlinear medium is Among them, second light combining means 42 'for combining only light of optical frequencies 2ν ₁ , 2ν ₂ ,... 2ν _N with the output light from the second pumping light source and inputting it again to the second-order nonlinear optical medium. The multi-wavelength collective wavelength converter and the multi-wavelength collective wavelength conversion method are used as solving means.

第５の発明の構成では、第２の合波手段４２’により二次光非線形媒質１３から出力される和周波光、多波長入力信号光及び第１の励起光のうち、多波長入力信号光及び第１の励起光はそのまま外部へ放出し、和周波光のみを第２の励起光とともに二次光非線形媒質１３に再び入力する。但し、第２の励起光及び和周波光は変換光に混入するため、前記同様、第１の合波手段４１の前段に波長可変フィルタを設けて遮断する必要がある。 In the configuration of the fifth invention , the multi-wavelength input signal light out of the sum frequency light, the multi-wavelength input signal light, and the first pumping light output from the secondary optical nonlinear medium 13 by the second multiplexing means 42 ′ is used. The first excitation light is emitted to the outside as it is, and only the sum frequency light is input to the secondary optical nonlinear medium 13 together with the second excitation light. However, since the second excitation light and the sum frequency light are mixed in the converted light, it is necessary to provide a wavelength variable filter in front of the first multiplexing means 41 and block it as described above.

また、第６の発明では、図５に示すように、２以上の整数Ｎに対して、任意の光周波数２ν₁−ν_P1，２ν₂−ν_P1，……２ν_N−ν_P1の多波長入力信号光をそれぞれ任意の光周波数２ν₁−ν_P2，２ν₂−ν_P2，……２ν_N−ν_P2の多波長変換光に変換する多波長一括波長変換器であって、光周波数ν_P1の第１の励起光源１１と、光周波数ν_P2の第２の励起光源１２と、二次高調波光発生効率が極大となる光周波数としてν₁，ν₂，……ν_Nを含む第１及び第２の二次光非線形媒質２１及び２２と、多波長入力信号光を直交する２つの偏波に分離し、そのうちの一方を前記第１の励起光源からの出力光の一部と合波して前記第１の二次光非線形媒質の一端へ入力し、他方を前記第１の励起光源からの出力光の一部と合波して前記第２の二次光非線形媒質の一端へ入力する、もしくは多波長入力信号光と前記第１の励起光源からの出力光とを合波するとともに直交する２つの偏波に分離し、そのうちの一方を前記第１の二次光非線形媒質の一端へ入力し、他方を前記第２の二次光非線形媒質の一端へ入力する第１の合分波手段５１と、前記第１の二次光非線形媒質の他端からの出力光と前記第２の励起光源からの出力光の一部とを合波して前記第２の二次光非線形媒質の他端へ入力し、前記第２の二次光非線形媒質の他端からの出力光と前記第２の励起光源からの出力光の一部とを合波して前記第１の二次光非線形媒質の他端へ入力する第２の合分波手段５２とを有する多波長一括波長変換器及びその多波長一括波長変換方法をもって解決手段とする。 In the sixth invention , as shown in FIG. 5, for an integer N of 2 or more, multiple wavelengths of arbitrary optical frequencies 2ν ₁ −ν _P1 , 2ν ₂ −ν _P1 ,... 2ν _N −ν _P1 . A multi-wavelength batch wavelength converter that converts input signal light into multi-wavelength converted light of arbitrary optical frequencies 2ν ₁ −ν _P2 , 2ν ₂ −ν _P2 ,... 2ν _N −ν _P2 , and has an optical frequency ν _P1. a first pumping light source 11, a second pumping light source 12 of the optical frequency [nu _P2, ₁ [nu as an optical frequency second harmonic light generation efficiency becomes maximum, [nu _2, the first and the ...... ν _N The second secondary optical nonlinear medium 21 and 22 and the multi-wavelength input signal light are separated into two orthogonally polarized waves, and one of them is combined with a part of the output light from the first pumping light source. The first secondary light nonlinear medium is input to one end, and the other is combined with a part of the output light from the first excitation light source to combine the second secondary light nonlinear medium. Input to one end of the medium, or combine multi-wavelength input signal light and output light from the first excitation light source and separate them into two orthogonal polarizations, one of which is the first secondary A first multiplexing / demultiplexing means 51 that inputs to one end of the optical nonlinear medium and inputs the other to one end of the second secondary optical nonlinear medium, and an output from the other end of the first secondary optical nonlinear medium Light and a part of the output light from the second pumping light source are combined and input to the other end of the second secondary optical nonlinear medium, and from the other end of the second secondary optical nonlinear medium And a second multiplexing / demultiplexing means 52 that multiplexes a part of the output light from the second pumping light source and inputs it to the other end of the first secondary nonlinear medium. The solution is a wavelength batch wavelength converter and a multi-wavelength batch wavelength conversion method.

第６の発明の構成では、和周波光／差周波光発生過程を、入力信号光を直交する２つの偏波に分離した状態で、それぞれ第１及び第２の二次光非線形媒質２１及び２２の往路／復路を用いて行う。即ち、第１の二次光非線形媒質２１に多波長入力信号光の一方の偏波成分と第１の励起光が入力され、また、第２の二次光非線形媒質２２に多波長入力信号光の他方の偏波成分と第１の励起光が入力され、それぞれ和周波光発生過程により和周波光が発生し、第１の二次光非線形媒質２１で発生した和周波光と第２の励起光が第２の二次光非線形媒質２２に再び入力され、また、第２の二次光非線形媒質２２で発生した和周波光と第２の励起光が第１の二次光非線形媒質２１に再び入力され、それぞれ差周波光発生過程により多波長変換光を得て、これらが合波される。変換光の光パワーが入力信号光の偏波状態に依存せず、一定の変換効率が保持される。 In the configuration of the sixth aspect of the invention , the first and second secondary nonlinear optical media 21 and 22 are respectively generated in the state where the sum frequency light / difference frequency light generation process is separated into two polarized waves orthogonal to each other. This is done using the forward / return route. That is, one polarization component of the multi-wavelength input signal light and the first pumping light are input to the first secondary optical nonlinear medium 21, and the multi-wavelength input signal light is input to the second secondary optical nonlinear medium 22. The other polarization component and the first pumping light are input, the sum frequency light is generated by the sum frequency light generation process, and the sum frequency light generated by the first secondary light nonlinear medium 21 and the second pumping light are generated. The light is input again to the second secondary optical nonlinear medium 22, and the sum frequency light and the second excitation light generated in the second secondary optical nonlinear medium 22 are input to the first secondary optical nonlinear medium 21. The signals are inputted again, and multi-wavelength converted lights are obtained by the difference frequency light generation process, and are combined. The optical power of the converted light does not depend on the polarization state of the input signal light, and a constant conversion efficiency is maintained.

また、第６の発明の構成では、第１、第２及び第４の発明の構成と同様、最終的に出力される多波長変換光には多波長入力信号光、第１、第２の励起光及び和周波光が混入しているため、第１の合分波手段５１の前段に、波長可変フィルタを設けて変換光のみを出力するようにする必要がある。 In the configuration of the sixth invention, as in the configurations of the first, second, and fourth inventions , the multi-wavelength converted light that is finally output includes the multi-wavelength input signal light, the first and second pumps. Since light and sum frequency light are mixed, it is necessary to provide a wavelength tunable filter before the first multiplexing / demultiplexing means 51 so as to output only the converted light.

この点を考慮し、第７の発明では、図５に示すように、第６の発明において、前記第１の二次光非線形媒質の他端からの出力光のうち光周波数２ν₁，２ν₂，……２ν_Nの光のみを前記第２の励起光源からの出力光の一部と合波して前記第２の二次光非線形媒質の他端へ入力し、前記第２の二次光非線形媒質の他端からの出力光のうち光周波数２ν₁，２ν₂，……２ν_Nの光のみを前記第２の励起光源からの出力光の一部と合波して前記第１の二次光非線形媒質の他端へ入力する第２の合分波手段５２’を有する多波長一括波長変換器及びその多波長一括波長変換方法をもって解決手段とする。 Considering this point, in the seventh invention , as shown in FIG. 5, in the sixth invention , the optical frequencies 2ν ₁ and 2ν ₂ of the output light from the other end of the first second-order nonlinear optical medium in the sixth invention . ,..., Only 2ν _N light is combined with a part of the output light from the second excitation light source and input to the other end of the second secondary light nonlinear medium, and the second secondary light is input. Of the output light from the other end of the nonlinear medium, only the light having the optical frequency 2ν ₁ , 2ν ₂ ,... 2ν _N is combined with a part of the output light from the second pumping light source, and the first two. The multi-wavelength collective wavelength converter having the second multiplexing / demultiplexing means 52 'for inputting to the other end of the next-order nonlinear medium and the multi-wavelength collective wavelength conversion method are used as the solution means.

第７の発明の構成では、第２の合分波手段５２’により第１及び第２の二次光非線形媒質２１及び２２から出力される和周波光、多波長入力信号光及び第１の励起光のうち、多波長入力信号光及び第１の励起光はそのまま外部へ放出し、和周波光のみを第２の励起光とともに第１及び第２の二次光非線形媒質２１及び２２に再び入力する。但し、第２の励起光及び和周波光は変換光に混入するため、前記同様、第１の合分波手段５１の前段に波長可変フィルタを設けて遮断する必要がある。 In the configuration of the seventh invention , the sum frequency light, the multi-wavelength input signal light and the first pumping light output from the first and second secondary optical nonlinear media 21 and 22 by the second multiplexing / demultiplexing means 52 ′. Of the light, the multi-wavelength input signal light and the first excitation light are directly emitted to the outside, and only the sum frequency light is input to the first and second secondary nonlinear media 21 and 22 together with the second excitation light. To do. However, since the second excitation light and the sum frequency light are mixed in the converted light, it is necessary to provide a wavelength variable filter in front of the first multiplexing / demultiplexing means 51 and cut it off as described above.

なお、第４乃至第７の発明の構成では、多波長変換光が多波長入力信号光の入力光路上を逆方向に伝搬するため、そのままでは多波長変換光を使用できない。 In the configurations of the fourth to seventh inventions , since the multi-wavelength converted light propagates in the reverse direction on the input optical path of the multi-wavelength input signal light, the multi-wavelength converted light cannot be used as it is.

この点を考慮し、第８の発明では、図６に示すように、第４乃至第７の発明（図では第４又は第５の発明）において、多波長入力信号光と多波長変換光とが互いに逆方向に伝搬する部分に、伝搬方向に応じて光を２つの方路に分離する光非可逆回路６１を挿入した多波長一括波長変換器及びその多波長一括波長変換方法をもって解決手段とする。 Considering this point, in the eighth invention , as shown in FIG. 6, in the fourth to seventh inventions ( the fourth or fifth invention in the figure), the multiwavelength input signal light and the multiwavelength converted light A multi-wavelength collective wavelength converter in which an optical irreversible circuit 61 for separating light into two directions according to the propagation direction is inserted in a portion in which the signals are propagated in opposite directions, and a solution means using the multi-wavelength collective wavelength conversion method To do.

第８の発明の構成では、ポートＡから入力された光はポートＢのみへ出力し、ポートＢから入力された光はポートＣのみへ出力し、ポートＣから入力された光はポートＡのみへ出力する光サーキュレータなどの光非可逆回路６１により、多波長変換光を多波長入力信号光から分離して取り出す。 In the configuration of the eighth invention, the light inputted from the port A is output to only the port B, the light input from the port B is output to only the port C, the light input from the port C to only the port A The multi-wavelength converted light is separated from the multi-wavelength input signal light by the optical irreversible circuit 61 such as an optical circulator for outputting.

なお、図６では、第１の合波回路４１と二次光非線形媒質１３との間に光非可逆回路６１を設けたが、第１の合波回路４１の前段に設けても良い。 In FIG. 6, the optical irreversible circuit 61 is provided between the first multiplexing circuit 41 and the secondary optical nonlinear medium 13, but it may be provided before the first multiplexing circuit 41.

変換光の光周波数を変化させる際には、第２の励起光の光周波数を変化させると同時に、波長可変フィルタの透過波長も必要な変換光のみを出力するように制御する必要があるため、構成の複雑化、波長可変フィルタの動作速度による変換先波長切換速度の制限などの問題がある。 When changing the optical frequency of the converted light, it is necessary to control the transmission wavelength of the wavelength tunable filter to output only the necessary converted light at the same time as changing the optical frequency of the second excitation light. There are problems such as complication of the configuration and limitation of the conversion wavelength switching speed due to the operating speed of the wavelength tunable filter.

この点を考慮し、第９の発明では、図７に示すように、第１乃至第８の発明（図では第５の発明＋第８の発明）において、多波長変換光の出力光路に、光周波数ν₁，ν₂，……ν_N付近にカットオフ光周波数を有する長波長帯透過フィルタ７１又は光周波数ν₁，ν₂，……ν_N付近にカットオフ光周波数を有する短波長帯透過フィルタ７１を挿入した多波長一括波長変換器及びその多波長一括波長変換方法をもって解決手段とする。 Considering this point, in the ninth invention , as shown in FIG. 7, in the first to eighth inventions ( fifth invention + eighth invention in the figure), in the output optical path of the multi-wavelength converted light, Optical wavelength ν ₁ , ν ₂ ,... Long wavelength band transmission filter 71 having a cutoff optical frequency near ν _N or optical frequencies ν ₁ , ν ₂ ,..., Short wavelength band having a cutoff optical frequency near ν _N The multi-wavelength batch wavelength converter having the transmission filter 71 inserted therein and the multi-wavelength batch wavelength conversion method are used as the solving means.

第９の発明の構成では、例えば図８に示すようなＱＰＭ光周波数（ν₁，ν₂，……ν_N）付近にそのカットオフ光周波数を有する長波長帯透過光フィルタ７１を多波長変換光の出力光路に挿入する。図７に示す構成における基本動作は第５の発明＋第８の発明の構成と同様であり、往路／復路でそれぞれ和周波光／差周波光発生を行う。多波長入力信号光及び第１の励起光は第２の合波手段により外部へ放出されるが、第２の励起光及び和周波光は光非可逆回路６１から出力される変換光に混入する。これを図８に示す波長特性の光フィルタ７１を用いて取り除くことができ、多波長変換光のみを出力することができる。但し、この例では、変換先波長は二次光非線形媒質のＱＰＭ波長より長波長側に制限される。 In the ninth aspect of the invention , a long wavelength band transmission optical filter 71 having the cutoff optical frequency in the vicinity of the QPM optical frequency (ν ₁ , ν ₂ ,..., Ν _N ) as shown in FIG. Insert into the light output optical path. Basic operation of the configuration shown in FIG. 7 is similar to the configuration of the invention of the fifth aspect + 8 performs sum frequency light / difference frequency light generated respectively in the forward / backward. The multi-wavelength input signal light and the first excitation light are emitted to the outside by the second multiplexing means, but the second excitation light and the sum frequency light are mixed in the converted light output from the optical irreversible circuit 61. . This can be removed by using the optical filter 71 having the wavelength characteristics shown in FIG. 8, and only the multi-wavelength converted light can be output. However, in this example, the conversion destination wavelength is limited to the longer wavelength side than the QPM wavelength of the secondary optical nonlinear medium.

なお、変換先波長が二次光非線形媒質のＱＰＭ波長より短波長側の場合は、ＱＰＭ光周波数（ν₁，ν₂，……ν_N）付近にそのカットオフ光周波数を有する短波長帯透過光フィルタを用いる。 When the conversion destination wavelength is shorter than the QPM wavelength of the secondary optical nonlinear medium, transmission in a short wavelength band having the cutoff optical frequency near the QPM optical frequency (ν ₁ , ν ₂ ,..., Ν _N ). Use an optical filter.

以上に説明したように、本発明の多波長一括波長変換器を用いることで、任意の波長の多波長入力信号光を一括して任意の波長の多波長変換光へ変換することが可能となる。 As described above, by using the multi-wavelength collective wavelength converter of the present invention, it becomes possible to collectively convert multi-wavelength input signal light having an arbitrary wavelength into multi-wavelength converted light having an arbitrary wavelength. .

図９は本発明の多波長一括波長変換器の第１の実施の形態、ここでは第１の発明に対応する実施の形態を示すもので、波長変換器への入力信号光として、変調速度１０Ｇｂｐｓ、波長多重数が４波、多重光周波数間隔Δν＝１００ＧＨｚ、各波長の信号光中心光周波数ν_S1，ν_S2，ν_S3，ν_S4の波長多重信号光を仮定し、この多波長入力信号光を一括でそれぞれ光周波数ν_C1，ν_C2，ν_C3，ν_C4に変換する場合を想定する。 FIG. 9 shows a first embodiment of a multi-wavelength batch wavelength converter according to the present invention, here an embodiment corresponding to the first invention . As an input signal light to the wavelength converter, a modulation rate of 10 Gbps is shown. Assuming wavelength multiplexed signal light having a wavelength multiplexing number of 4 waves, a multiplexed optical frequency interval Δν = 100 GHz, and signal light center optical frequencies ν _S1 , ν _S2 , ν _S3 , ν _S4 of each wavelength, this multi-wavelength input signal light Are collectively converted to optical frequencies ν _C1 , ν _C2 , ν _C3 , and ν _C4 , respectively.

図中、１０１は光周波数ν_P1の第１の励起光源、１０２は光周波数ν_P2の第２の励起光源、１０３は二次光非線形媒質、１０４，１０５はエルビウムドープ光ファイバアンプ（ＥＤＦＡ）、１０６，１０７は方向性結合器、１０８は波長可変バンドパスフィルタ（ＢＰＦ）である。 In the figure, 101 is a first pumping light source having an optical frequency ν _P1 , 102 is a second pumping light source having an optical frequency ν _P2 , 103 is a secondary optical nonlinear medium, 104 and 105 are erbium-doped optical fiber amplifiers (EDFA), 106 and 107 are directional couplers, and 108 is a wavelength tunable bandpass filter (BPF).

前記構成において、第１の励起光源１０１及び第２の励起光源１０２からの励起光は、ＥＤＦＡ１０４及び１０５にて増幅された後、方向性結合器１０６及び１０７を介して多波長入力信号光と合波され、二次光非線形媒質１０３に入力される。二次光非線形媒質１０３における和周波光発生過程と差周波光発生過程により発生した多波長変換光は、波長可変ＢＰＦ１０８を透過して出力される。 In the above configuration, the excitation light from the first excitation light source 101 and the second excitation light source 102 is amplified by the EDFAs 104 and 105 and then combined with the multi-wavelength input signal light via the directional couplers 106 and 107. Wave is input to the second-order nonlinear optical medium 103. The multi-wavelength converted light generated by the sum frequency light generation process and the difference frequency light generation process in the secondary light nonlinear medium 103 is transmitted through the wavelength variable BPF 108 and output.

図１０は多波長入力信号光及び二次光非線形媒質の光周波数の配置の一例を示すものである。 FIG. 10 shows an example of the arrangement of the optical frequencies of the multi-wavelength input signal light and the secondary optical nonlinear medium.

ここでは二次光非線形媒質１０３として、図１０に示すように、二次高調波光発生効率が最大となる擬似位相整合光周波数を、光周波数間隔Δν／２＝５０ＧＨｚで光周波数ν₁，ν₂，ν₃，ν₄に４本有するマルチ擬似位相整合ニオブ酸リチウム導波路（マルチ擬似位相整合ＬＮＷＧ）を利用する。 Here, as the second-order nonlinear optical medium 103, as shown in FIG. 10, the quasi-phase-matched optical frequency that maximizes the second-order harmonic light generation efficiency is set to the optical frequencies ν ₁ and ν ₂ at the optical frequency interval Δν / 2 = 50 GHz. , Ν ₃ , ν ₄ , a multi quasi phase matching lithium niobate waveguide (multi quasi phase matching LNWG) is used.

通常、擬似位相整合光周波数は１つのみであるが、近年、複数本の位相整合光周波数を実現する手法が提案され、実際に作製されている（例えば、参考文献：M.Asobe, et.al., Optics Letters, Vol.558-561, 2003）。以下にその製法例を示す。 Usually, there is only one quasi-phase-matched optical frequency, but in recent years, a method for realizing a plurality of phase-matched optical frequencies has been proposed and actually manufactured (for example, reference: M. Asobe, et. al., Optics Letters, Vol. 558-561, 2003). An example of the production method is shown below.

マルチ擬似位相整合（ＱＰＭ）素子は、電界印加によって分極反転構造を形成したニオブ酸リチウム基板に光導波路を形成することにより作製できる。マルチＱＰＭ素子を実現するための分極反転構造としては、前記参考文献に述べられているように周期分極反転構造に連続的な位相変調を施し、その構造を別の周期で繰り返すことにより実現できる。以下に素子の作製手順の例を示す。 A multi quasi phase matching (QPM) element can be produced by forming an optical waveguide on a lithium niobate substrate having a domain-inverted structure formed by applying an electric field. The polarization inversion structure for realizing the multi-QPM element can be realized by subjecting the periodic polarization inversion structure to continuous phase modulation as described in the above-mentioned reference, and repeating the structure with another period. An example of a manufacturing procedure of the element is shown below.

本実施の形態ではＬｉＮｂＯ₃のＺ板（Ｚ軸に垂直な面となるように切り出された基板）を用い、分極反転部を電界印加法により基本周期１５．５μｍで分極反転した。分極反転した基板にＳｉＯ₂をフォトリソグラフィ技術を用いてパターン化し、温度約１８０度で安息香酸中に浸漬したのちに、酸素雰囲気中で熱処理してプロトン交換導波路を形成した。本実施の形態では４つの励起波長に対応できるように装置を構成した。分極反転部の詳細を以下に述べる。 In this embodiment, a LiNbO ₃ Z plate (a substrate cut out so as to be a plane perpendicular to the Z axis) was used, and the polarization inversion portion was subjected to polarization inversion at a basic period of 15.5 μm by an electric field application method. SiO ₂ was patterned on the polarization-reversed substrate using a photolithography technique, immersed in benzoic acid at a temperature of about 180 ° C., and then heat-treated in an oxygen atmosphere to form a proton exchange waveguide. In the present embodiment, the apparatus is configured to support four excitation wavelengths. Details of the polarization inversion portion will be described below.

１．５５μｍで第二次高調波発生（ＳＨＧ）を行った場合の位相整合ピークの周波数間隔が５０ＧＨｚとなるように位相変調周期を２８．５２μｍとし、分極反転部の全体の長さを５７．０４μｍとして位相変調パターンが２周期分繰り返すようにした。位相変調パターン１周期当たりに配置される分極反転構造は１８４０周期となる。本実施の形態ではこの周期１５．５μｍの分極反転構造を４周期ごとを単位として、位相変調周期を４６０分割してそれぞれの分極反転構造単位ごとの位相を最適化して４つの励起波長において最大の変換効率が得られる構造とした。 When the second harmonic generation (SHG) is performed at 1.55 μm, the phase modulation period is set to 28.52 μm so that the frequency interval of the phase matching peak is 50 GHz, and the entire length of the polarization inversion unit is 57. The phase modulation pattern was repeated for two periods as 04 μm. The domain-inverted structure arranged per period of the phase modulation pattern is 1840 periods. In the present embodiment, the polarization inversion structure with a period of 15.5 μm is divided into units of every four periods, the phase modulation period is divided into 460, and the phase for each of the domain inversion structure units is optimized to obtain the maximum at the four excitation wavelengths. The conversion efficiency is obtained.

本実施の形態に用いた分極反転構造を有するＬｉＮｂＯ₃基板の作成方法を簡単に説明する。ＬｉＮｂＯ₃基板の＋Ｚ面にレジストを塗布し、フォトリソグラフィ技術を用いてパターン化し、電極を蒸着し、基板の両側に電解液を接触させて、電界を印加してレジストのない電極が基板に直接触れている部分の分極を反転する。 A method for producing a LiNbO ₃ substrate having a domain-inverted structure used in this embodiment will be briefly described. A resist is applied to the + Z surface of the LiNbO ₃ substrate, patterned using photolithography technology, electrodes are deposited, an electrolyte is brought into contact with both sides of the substrate, an electric field is applied, and the resist-free electrode is directly applied to the substrate. Inverts the polarization of the touched part.

上記のような製法にて作製されたマルチＱＰＭ−ＬＮＷＧを用いることで、多波長入力信号光に対しても任意波長変換が可能になる。原理の詳細を示す。 By using the multi-QPM-LNWG produced by the manufacturing method as described above, arbitrary wavelength conversion is possible even for multi-wavelength input signal light. Details of the principle are shown.

ＱＰＭ−ＬＮＷＧにおける第１の励起光と多波長入力信号光の各光周波数ν_S1〜ν_S4の光との和周波光発生効率ηは、比例係数ｃを用いて近似的に式（１）のように表される。 The sum frequency light generation efficiency η of the first pumping light and the light of each wavelength ν _{S1 to} ν _S4 of the multi-wavelength input signal light in the QPM-LNWG is approximately expressed by the equation (1) using the proportional coefficient c. It is expressed as follows.

ここで、β（ν_Sn）は各信号光の伝搬定数、β（ν_P1）は第１の励起光の伝搬定数、β（ν_Sk＋ν_P1）は両者の和周波光の伝搬定数、ＬはＱＰＭ−ＬＮＷＧ１０３の導波路長である。また、Δβ_n0は光学軸反転周期により一意に決定される定数であり、次式のように表される。 Where β (ν _Sn ) is the propagation constant of each signal light, β (ν _P1 ) is the propagation constant of the first excitation light, β (ν _Sk + ν _P1 ) is the propagation constant of the sum frequency light of both, and L is It is the waveguide length of QPM-LNWG103. Δβ _n0 is a constant uniquely determined by the optical axis inversion period, and is represented by the following equation.

ここで、多波長入力信号光の光周波数間隔はＱＰＭ−ＬＮＷＧ１０３の擬似位相整合光周波数間隔の２倍であるため、任意のｎに対してν_Sn＋ν_P1＝２ν_nを満たすように、第１の励起光の光周波数ν_P1を設定することが可能である。 Here, since the optical frequency interval of the multi-wavelength input signal light is twice the quasi-phase matched optical frequency interval of the QPM-LNWG 103, the first frequency so as to satisfy ν _Sn + ν _P1 = 2ν _n for any _n . It is possible to set the optical frequency ν _P1 of the excitation light.

これを用いて、式（１）を式（３）のように変形できる。 Using this, equation (1) can be transformed into equation (3).

さらに、ν_Snはν_n近傍の光周波数（｜ν_Sn／ν_n−１｜≪１）であると仮定し、β（ν）をν_n近傍で展開し、高次の項を無視することで、式（３）は式（４）のように変形できる。 Furthermore, ν _Sn is assumed to have an optical frequency near ν _n (| ν _Sn / ν _n −1 | << 1), β (ν) is developed near ν _n , and higher-order terms are ignored. Thus, equation (3) can be transformed into equation (4).

従って、ν_Snが十分にν_n近傍（｜ν_Sn／ν_n−１｜≪１）である場合、光周波数ν_P1の第１の励起光を用いることで、任意の光周波数ν_Snの信号光に対して高効率な和周波発生が可能であることが分かる。 Therefore, [nu _Sn is sufficiently [nu _n vicinity when it is _{_{(| | ν Sn / ν n}} -1 «1), by using the first excitation light optical frequency [nu _P1, signals of any optical frequency [nu _Sn It can be seen that highly efficient sum frequency generation is possible for light.

図１１は和周波光発生及び差周波光発生のようすを示すものである。 FIG. 11 shows the generation of sum frequency light and difference frequency light.

図１１（ａ）に示すように、和周波光発生により各光周波数ν_Snの信号光はそれぞれ光周波数２ν_nの信号光に変換される。さらに、それぞれの和周波光と第２の励起光の差周波光発生によって、変換光を得る。第２の励起光の光周波数ν_P2として、任意のｎに対してν_Cn＋ν_P2＝２ν_nを満たすようにν_P2を設定することが可態であり、この過程においても上記と同様な原理により、擬似位相整合が満たされ、高効率な差周波光発生が実現する（図１１（ｂ））。 As shown in FIG. 11A, the signal light of each optical frequency ν _Sn is converted into the signal light of optical frequency 2ν _n by the sum frequency light generation. Further, converted light is obtained by generating a difference frequency light between each sum frequency light and the second excitation light. It is possible to set ν _P2 so as to satisfy ν _Cn + ν _P2 = 2ν _n for an arbitrary n as the optical frequency ν _P2 of the second pumping light. In this process, the same principle as above is used. Thus, the quasi-phase matching is satisfied, and high-efficiency difference frequency light generation is realized (FIG. 11B).

また、変換先光周波数はν_P2を変化させることで制御可能であるが、ν_P2に無関係に擬似位相整合が満たされるため、任意のν_P2に対して高い和周波／差周波光発生効率が維持され、変換先光周波数を変化させても変換光のパワーが変動することは無い。また、ここでは、擬似位相整合光周波数を多重光周波数間隔Δνの半分としたが、整数分の１でも良い。 Also, although the destination optical frequency is controllable by varying the [nu _P2, because it satisfied irrespective quasi-phase matching in [nu _P2, higher sum frequency / difference frequency light generation efficiency for any [nu _P2 The power of the converted light does not fluctuate even if the conversion destination optical frequency is changed. Here, the quasi phase matching optical frequency is half of the multiple optical frequency interval Δν, but may be a fraction of an integer.

図１２は本発明の多波長一括波長変換器の第２の実施の形態、ここでは第７の発明に対応する実施の形態を示すもので、図中、１１１は第１の励起光源、１１２は第２の励起光源、１１３は第１の二次光非線形媒質（ＱＰＭ−ＬＮＷＧ）、１１４は第２の二次光非線形媒質（ＱＰＭ−ＬＮＷＧ）、１１５，１１６はＥＤＦＡ、１１７は合波器、１１８は偏光依存型ビームスプリッタ（ＰＢＳ）、１１９は偏光回転子、１２０はビームスプリッタ、１２１は７８０ｎｍ帯の光を反射し、１５５０ｎｍ帯の光を透過するミラーである。 FIG. 12 shows a second embodiment of the multi-wavelength batch wavelength converter of the present invention, here an embodiment corresponding to the seventh invention , in which 111 is the first excitation light source, 112 is The second pumping light source, 113 is a first secondary optical nonlinear medium (QPM-LNWG), 114 is a second secondary optical nonlinear medium (QPM-LNWG), 115 and 116 are EDFAs, 117 is a multiplexer, 118 is a polarization-dependent beam splitter (PBS), 119 is a polarization rotator, 120 is a beam splitter, and 121 is a mirror that reflects light in the 780 nm band and transmits light in the 1550 nm band.

ここで、合波器１１７、ＰＢＳ１１８及び偏光回転子１１９が第７の発明でいう第１の合分波手段を構成し、ビームスプリッタ１２０及びミラー１２１が第７の発明でいう第２の合分波手段を構成する。 Here, the multiplexer 117, the PBS 118, and the polarization rotator 119 constitute the first multiplexing / demultiplexing means referred to in the seventh invention , and the beam splitter 120 and the mirror 121 are the second multiplexing / demultiplexing referred to in the seventh invention. Constitutes wave means.

前記構成において、多波長入力信号光は、第１の励起光源１１１で発生し、ＥＤＦＡ１１５で増幅された第１の励起光と合波器１１７で合波された後、偏光ビームスプリッタ（ＰＢＳ）１１８により２つの直交偏波に分離される。一方の偏波成分はそのままＱＰＭ−ＬＮＷＧ１１３に入力され、他方の偏波成分は偏光回転子１１９により９０度回転されてＱＰＭ−ＬＮＷＧ１１４に入力され、それぞれ和周波光発生を起こす。 In the above-described configuration, the multi-wavelength input signal light is generated by the first pumping light source 111, combined with the first pumping light amplified by the EDFA 115 by the multiplexer 117, and then the polarization beam splitter (PBS) 118. Is separated into two orthogonally polarized waves. One polarization component is input to the QPM-LNWG 113 as it is, and the other polarization component is rotated 90 degrees by the polarization rotator 119 and input to the QPM-LNWG 114 to cause sum frequency light generation.

それぞれのＱＰＭ−ＬＮＷＧ１１３，１１４からの出力光のうち、和周波光のみがミラー１２１により反射され、互いに他方のＱＰＭ−ＬＮＷＧ１１４，１１３に入力される。この際、第２の励起光源１１２で発生し、ＥＤＦＡ１１６で増幅され、ビームスプリッタ１２０で等しく分波された第２の励起光と合波される。 Of the output light from each of the QPM-LNWGs 113 and 114, only the sum frequency light is reflected by the mirror 121 and input to the other QPM-LNWG 114 and 113. At this time, the light is generated by the second excitation light source 112, amplified by the EDFA 116, and multiplexed with the second excitation light equally divided by the beam splitter 120.

それぞれのＱＰＭ−ＬＮＷＧ１１３，１１４において、入力された和周波光と第２の励起光は、和周波光発生過程とは反対方向に伝搬し、差周波光発生を起こす。発生した差周波光はＰＢＳ１１８により合波され、多波長変換光となってＰＢＳ１１８の入力信号光入力ポートから出力される。その後、図示しない光非可逆回路により入力光路から分離され、出力される。 In each of the QPM-LNWGs 113 and 114, the input sum frequency light and the second excitation light propagate in the opposite direction to the sum frequency light generation process and cause difference frequency light generation. The generated difference frequency light is multiplexed by the PBS 118, and converted into multi-wavelength converted light, which is output from the input signal light input port of the PBS 118. Thereafter, the light is separated from the input optical path by an optical non-reciprocal circuit (not shown) and output.

この構成では、入力信号光は直交する２つの偏波に分離され、個々に波長変換された後に合波されるため、任意の偏波状態に対して一定の変換効率を保持できる。 In this configuration, the input signal light is separated into two orthogonal polarizations, and after being individually wavelength-converted, the input signal light is multiplexed, so that a constant conversion efficiency can be maintained for any polarization state.

なお、光非可逆回路の挿入位置はＰＢＳ１１８と合波器１１７との間、合波器１１７の前段のいずれでも良い。また、図１２では多波長入力信号光を第１の励起光と合波した後に直交する２つの偏波に分離しているが、多波長入力信号光のみを直交する２つの偏波に分離し、その後、それぞれに対して第１の励起光を合波するようにしても良い。 The insertion position of the optical irreversible circuit may be either between the PBS 118 and the multiplexer 117, or before the multiplexer 117. In FIG. 12, the multi-wavelength input signal light is separated into two orthogonal polarizations after being combined with the first excitation light, but only the multi-wavelength input signal light is separated into two orthogonal polarizations. Thereafter, the first excitation light may be multiplexed for each of them.

第１の発明の多波長一括波長変換器の概要を示す構成図 The block diagram which shows the outline | summary of the multi-wavelength batch wavelength converter of 1st invention 第２の発明の多波長一括波長変換器の概要を示す構成図 The block diagram which shows the outline | summary of the multi-wavelength batch wavelength converter of 2nd invention 第３の発明の多波長一括波長変換器の概要を示す構成図 The block diagram which shows the outline | summary of the multi-wavelength batch wavelength converter of 3rd invention 第４、第５の発明の多波長一括波長変換器の概要を示す構成図Configuration diagram showing an outline of the multi-wavelength batch wavelength converter of the fourth and fifth inventions 第６、第７の発明の多波長一括波長変換器の概要を示す構成図Configuration diagram showing an outline of a multi-wavelength batch wavelength converter of the sixth and seventh inventions 第８の発明の多波長一括波長変換器の概要を示す構成図 The block diagram which shows the outline | summary of the multi-wavelength batch wavelength converter of 8th invention 第９の発明の多波長一括波長変換器の概要を示す構成図 The block diagram which shows the outline | summary of the multi-wavelength batch wavelength converter of 9th invention 波長固定フィルタの周波数特性の一例を示す特性図Characteristic diagram showing an example of frequency characteristics of a fixed wavelength filter 本発明の多波長一括波長変換器の第１の実施の形態を示す構成図The block diagram which shows 1st Embodiment of the multi-wavelength batch wavelength converter of this invention 多波長入力信号光及び二次光非線形媒質の光周波数の配置の一例を示す特性図Characteristic diagram showing an example of arrangement of optical frequencies of multi-wavelength input signal light and secondary optical nonlinear medium 和周波光発生及び差周波光発生のようすを示す説明図Explanatory drawing showing how sum frequency light generation and difference frequency light generation occur 本発明の多波長一括波長変換器の第２の実施の形態を示す構成図The block diagram which shows 2nd Embodiment of the multi-wavelength batch wavelength converter of this invention

１１，１０１，１１１：第１の励起光源、１２，１０２，１１２：第２の励起光源、１３，２１，２２，１１３，１１４：二次光非線形媒質、１４、２３，２４、４１，４２，４２’：合波手段、３１：光フィルタ、５１，５２，５２’：合分波手段、６１：光非可逆回路、７１：波長固定フィルタ、１０３：マルチ擬似位相整合ＬＮＷＧ、１０４，１０５，１１５，１１６：ＥＤＦＡ、１０６，１０７：方向性結合器、１０８：波長可変ＢＰＦ、１１７：合波器、１１８：ＰＢＳ、１１９：偏光回転子、１２０：ビームスプリッタ、１２１：ミラー。 11, 101, 111: first excitation light source, 12, 102, 112: second excitation light source, 13, 21, 22, 113, 114: secondary optical nonlinear medium, 14, 23, 24, 41, 42, 42 ': multiplexing means, 31: optical filter, 51, 52, 52': multiplexing / demultiplexing means, 61: optical irreversible circuit, 71: wavelength fixed filter, 103: multi-pseudo phase matching LNWG, 104, 105, 115 116: EDFA, 106, 107: directional coupler, 108: wavelength tunable BPF, 117: multiplexer, 118: PBS, 119: polarization rotator, 120: beam splitter, 121: mirror.

Claims

２以上の整数Ｎに対して、任意の光周波数２ν₁−ν_P1，２ν₂−ν_P1，……２ν_N−ν_P1の多波長入力信号光をそれぞれ任意の光周波数２ν₁−ν_P2，２ν₂−ν_P2，……２ν_N−ν_P2の多波長変換光に変換する多波長一括波長変換器であって、
光周波数ν_P1の第１の励起光源と、
光周波数ν_P2の第２の励起光源と、
二次高調波光発生効率が極大となる光周波数としてν₁，ν₂，……ν_Nを含む二次光非線形媒質と、
多波長入力信号光と前記第１の励起光源からの出力光と前記第２の励起光源からの出力光とを合波し、前記二次光非線形媒質へ入力する合波手段とを有する
ことを特徴とする多波長一括波長変換器。 For two or more integer N, any optical frequency _{_{_{2ν 1 -ν P1, 2ν 2 -ν}}} P1, ...... 2ν N arbitrary optical frequency -v _P1 multi-wavelength input signal light of each 2v ₁ -v _P2, 2ν ₂ −ν _P2 ............ Multi-wavelength batch wavelength converter that converts to 2ν _N −ν _P2 multi-wavelength converted light,
A first excitation light source having an optical frequency ν _P1 ;
A second excitation light source of the optical frequency [nu _P2,
[Nu ₁ as an optical frequency second harmonic light generation efficiency becomes maximum, [nu _2, a secondary optical nonlinear medium comprising ...... ν _N,
A multiplexing means for combining the multi-wavelength input signal light, the output light from the first excitation light source, and the output light from the second excitation light source, and inputting the combined light to the secondary optical nonlinear medium. Multi-wavelength batch wavelength converter characterized.

２以上の整数Ｎに対して、任意の光周波数２ν₁−ν_P1，２ν₂−ν_P1，……２ν_N−ν_P1の多波長入力信号光をそれぞれ任意の光周波数２ν₁−ν_P2，２ν₂−ν_P2，……２ν_N−ν_P2の多波長変換光に変換する多波長一括波長変換器であって、
光周波数ν_P1の第１の励起光源と、
光周波数ν_P2の第２の励起光源と、
二次高調波光発生効率が極大となる光周波数としてν₁，ν₂，……ν_Nを含む第１及び第２の二次光非線形媒質と、
多波長入力信号光と前記第１の励起光源からの出力光とを合波し、前記第１の二次光非線形媒質へ入力する第１の合波手段と、
前記第１の二次光非線形媒質からの出力光と前記第２の励起光源からの出力光とを合波し、前記第２の二次光非線形媒質へ入力する第２の合波手段とを有する
ことを特徴とする多波長一括波長変換器。 For two or more integer N, any optical frequency _{_{_{2ν 1 -ν P1, 2ν 2 -ν}}} P1, ...... 2ν N arbitrary optical frequency -v _P1 multi-wavelength input signal light of each 2v ₁ -v _P2, 2ν ₂ −ν _P2 ............ Multi-wavelength batch wavelength converter that converts to 2ν _N −ν _P2 multi-wavelength converted light,
A first excitation light source having an optical frequency ν _P1 ;
A second excitation light source of optical frequency ν _P2 ;
First and second second-order nonlinear optical media including ν ₁ , ν ₂ , ν _N as optical frequencies at which the second-harmonic light generation efficiency is maximized;
First multiplexing means for multiplexing multi-wavelength input signal light and output light from the first pumping light source and inputting the multiplexed light to the first secondary optical nonlinear medium;
Second combining means for combining the output light from the first secondary light nonlinear medium and the output light from the second pumping light source and inputting the combined light to the second secondary light nonlinear medium; A multi-wavelength batch wavelength converter characterized by comprising:

請求項２記載の多波長一括波長変換器において、
前記第１の二次光非線形媒質と第２の合波手段との間に、光周波数２ν₁，２ν₂，……２ν_Nの光のみを透過する光フィルタを設けた
ことを特徴とする多波長一括波長変換器。 The multi-wavelength batch wavelength converter according to claim 2,
An optical filter that transmits only light having an optical frequency of 2ν ₁ , 2ν ₂ ,... 2ν _N is provided between the first secondary optical nonlinear medium and the second multiplexing means. Wavelength batch wavelength converter.

２以上の整数Ｎに対して、任意の光周波数２ν₁−ν_P1，２ν₂−ν_P1，……２ν_N−ν_P1の多波長入力信号光をそれぞれ任意の光周波数２ν₁−ν_P2，２ν₂−ν_P2，……２ν_N−ν_P2の多波長変換光に変換する多波長一括波長変換器であって、
光周波数ν_P1の第１の励起光源と、
光周波数ν_P2の第２の励起光源と、
二次高調波光発生効率が極大となる光周波数としてν₁，ν₂，……ν_Nを含む第１及び第２の二次光非線形媒質と、
多波長入力信号光を直交する２つの偏波に分離し、そのうちの一方を前記第１の励起光源からの出力光の一部と合波して前記第１の二次光非線形媒質の一端へ入力し、他方を前記第１の励起光源からの出力光の一部と合波して前記第２の二次光非線形媒質の一端へ入力する、もしくは多波長入力信号光と前記第１の励起光源からの出力光とを合波するとともに直交する２つの偏波に分離し、そのうちの一方を前記第１の二次光非線形媒質の一端へ入力し、他方を前記第２の二次光非線形媒質の一端へ入力する第１の合分波手段と、
前記第１の二次光非線形媒質の他端からの出力光と前記第２の励起光源からの出力光の一部とを合波して前記第２の二次光非線形媒質の他端へ入力し、前記第２の二次光非線形媒質の他端からの出力光と前記第２の励起光源からの出力光の一部とを合波して前記第１の二次光非線形媒質の他端へ入力する第２の合分波手段とを有する
ことを特徴とする多波長一括波長変換器。 For two or more integer N, any optical frequency _{_{_{2ν 1 -ν P1, 2ν 2 -ν}}} P1, ...... 2ν N arbitrary optical frequency -v _P1 multi-wavelength input signal light of each 2v ₁ -v _P2, 2ν ₂ −ν _P2 ............ Multi-wavelength batch wavelength converter that converts to 2ν _N −ν _P2 multi-wavelength converted light,
A first excitation light source having an optical frequency ν _P1 ;
A second excitation light source of optical frequency ν _P2 ;
First and second second-order nonlinear optical media including ν ₁ , ν ₂ , ν _N as optical frequencies at which the second-harmonic light generation efficiency is maximized;
The multi-wavelength input signal light is separated into two orthogonally polarized waves, and one of them is combined with a part of the output light from the first pumping light source to one end of the first secondary optical nonlinear medium. The other is combined with a part of the output light from the first excitation light source and input to one end of the second secondary optical nonlinear medium, or the multi-wavelength input signal light and the first excitation The output light from the light source is multiplexed and separated into two orthogonal polarized waves, one of which is input to one end of the first secondary optical nonlinear medium, and the other is input to the second secondary optical nonlinear First multiplexing / demultiplexing means for inputting to one end of the medium;
The output light from the other end of the first secondary light nonlinear medium and the part of the output light from the second excitation light source are combined and input to the other end of the second secondary light nonlinear medium. And combining the output light from the other end of the second secondary optical nonlinear medium and a part of the output light from the second pumping light source to combine the other end of the first secondary optical nonlinear medium. And a second wavelength multiplexing / demultiplexing means for inputting to the multi-wavelength batch wavelength converter.

請求項４記載の多波長一括波長変換器において、
前記第１の二次光非線形媒質の他端からの出力光のうち光周波数２ν₁，２ν₂，……２ν_Nの光のみを前記第２の励起光源からの出力光の一部と合波して前記第２の二次光非線形媒質の他端へ入力し、前記第２の二次光非線形媒質の他端からの出力光のうち光周波数２ν₁，２ν₂，……２ν_Nの光のみを前記第２の励起光源からの出力光の一部と合波して前記第１の二次光非線形媒質の他端へ入力する第２の合分波手段を有する
ことを特徴とする多波長一括波長変換器。 The multi-wavelength batch wavelength converter according to claim 4 ,
Wherein among light frequency 2v ₁ of the output light from the other end of the first secondary optical nonlinear medium, 2v _2, only light of ...... 2ν _N combined with the part of the output light from the second excitation light source And input to the other end of the second secondary optical nonlinear medium, and light having optical frequencies of 2ν ₁ , 2ν ₂ ,... 2ν _N out of the output light from the other end of the second secondary optical nonlinear medium. And a second multiplexing / demultiplexing unit that multiplexes only a part of the output light from the second excitation light source and inputs it to the other end of the first second-order nonlinear optical medium. Wavelength batch wavelength converter.

請求項４または５記載の多波長一括波長変換器において、
多波長入力信号光と多波長変換光とが互いに逆方向に伝搬する部分に、伝搬方向に応じて光を２つの方路に分離する光非可逆回路を挿入した
ことを特徴とする多波長一括波長変換器。 The multi-wavelength batch wavelength converter according to claim 4 or 5 ,
Multi-wavelength collective, characterized in that an optical non-reciprocal circuit that separates light into two directions according to the propagation direction is inserted in the part where multi-wavelength input signal light and multi-wavelength converted light propagate in opposite directions Wavelength converter.

請求項１乃至６いずれか記載の多波長一括波長変換器において、
多波長変換光の出力光路に、光周波数ν₁，ν₂，……ν_N付近にカットオフ光周波数を有する長波長帯透過フィルタ又は光周波数ν₁，ν₂，……ν_N付近にカットオフ光周波数を有する短波長帯透過フィルタを挿入した
ことを特徴とする多波長一括波長変換器。 The multi-wavelength batch wavelength converter according to any one of claims 1 to 6 ,
The output path of the multi-wavelength converted light, optical frequency ν _1, ν _2, ...... ν long wavelength transmission filter or optical frequency [nu ₁ having a cut-off light frequency around _N, [nu _2, cut around ...... [nu _N A multi-wavelength batch wavelength converter, wherein a short wavelength band transmission filter having an off-light frequency is inserted.

２以上の整数Ｎに対して、任意の光周波数２ν₁−ν_P1，２ν₂−ν_P1，……２ν_N−ν_P1の多波長入力信号光をそれぞれ任意の光周波数２ν₁−ν_P2，２ν₂−ν_P2，……２ν_N−ν_P2の多波長変換光に変換する多波長一括波長変換方法であって、
光周波数ν_P1の第１の励起光源と、
光周波数ν_P2の第２の励起光源と、
二次高調波光発生効率が極大となる光周波数としてν₁，ν₂，……ν_Nを含む二次光非線形媒質とを用い、
多波長入力信号光と前記第１の励起光源からの出力光と前記第２の励起光源からの出力光とを合波し、前記二次光非線形媒質へ入力する
ことを特徴とする多波長一括波長変換方法。 For two or more integer N, any optical frequency _{_{_{2ν 1 -ν P1, 2ν 2 -ν}}} P1, ...... 2ν N arbitrary optical frequency -v _P1 multi-wavelength input signal light of each 2v ₁ -v _P2, 2ν ₂ −ν _P2 ............ Multiple wavelength batch wavelength conversion method for converting into 2ν _N −ν _P2 multi-wavelength converted light,
A first excitation light source having an optical frequency ν _P1 ;
A second excitation light source of optical frequency ν _P2 ;
Using a second-order nonlinear optical medium including ν ₁ , ν ₂ , ν _N as the optical frequencies at which the second-harmonic light generation efficiency is maximized,
Multi-wavelength input signal light, output light from the first excitation light source, and output light from the second excitation light source are combined and input to the second-order nonlinear optical medium. Wavelength conversion method.

２以上の整数Ｎに対して、任意の光周波数２ν₁−ν_P1，２ν₂−ν_P1，……２ν_N−ν_P1の多波長入力信号光をそれぞれ任意の光周波数２ν₁−ν_P2，２ν₂−ν_P2，……２ν_N−ν_P2の多波長変換光に変換する多波長一括波長変換方法であって、
光周波数ν_P1の第１の励起光源と、
光周波数ν_P2の第２の励起光源と、
二次高調波光発生効率が極大となる光周波数としてν₁，ν₂，……ν_Nを含む第１及び第２の二次光非線形媒質とを用い、
多波長入力信号光と前記第１の励起光源からの出力光とを合波し、前記第１の二次光非線形媒質へ入力し、
前記第１の二次光非線形媒質からの出力光と前記第２の励起光源からの出力光とを合波し、前記第２の二次光非線形媒質へ入力する
ことを特徴とする多波長一括波長変換方法。 For two or more integer N, any optical frequency _{_{_{2ν 1 -ν P1, 2ν 2 -ν}}} P1, ...... 2ν N arbitrary optical frequency -v _P1 multi-wavelength input signal light of each 2v ₁ -v _P2, 2ν ₂ −ν _P2 ............ Multiple wavelength batch wavelength conversion method for converting into 2ν _N −ν _P2 multi-wavelength converted light,
A first excitation light source having an optical frequency ν _P1 ;
A second excitation light source of optical frequency ν _P2 ;
Using first and second second-order nonlinear optical media including ν ₁ , ν ₂ ,... Ν _N as optical frequencies at which the second-harmonic light generation efficiency is maximized,
Multi-wavelength input signal light and output light from the first excitation light source are combined and input to the first secondary optical nonlinear medium,
A multi-wavelength package characterized in that the output light from the first secondary light nonlinear medium and the output light from the second pumping light source are combined and input to the second secondary light nonlinear medium. Wavelength conversion method.

請求項９記載の多波長一括波長変換方法において、
前記第１の二次光非線形媒質からの出力光のうち光周波数２ν₁，２ν₂，……２ν_Nの光のみを前記第２の励起光源からの出力光と合波し、前記第２の二次光非線形媒質へ入力する
ことを特徴とする多波長一括波長変換方法。 In the multiple wavelength batch wavelength conversion method according to claim 9 ,
Of the output light from the first secondary optical nonlinear medium, only the light with optical frequencies 2ν ₁ , 2ν ₂ ,... 2ν _N is combined with the output light from the second excitation light source, and the second A multi-wavelength batch wavelength conversion method characterized by inputting to a secondary optical nonlinear medium.

２以上の整数Ｎに対して、任意の光周波数２ν₁−ν_P1，２ν₂−ν_P1，……２ν_N−ν_P1の多波長入力信号光をそれぞれ任意の光周波数２ν₁−ν_P2，２ν₂−ν_P2，……２ν_N−ν_P2の多波長変換光に変換する多波長一括波長変換方法であって、
光周波数ν_P1の第１の励起光源と、
光周波数ν_P2の第２の励起光源と、
二次高調波光発生効率が極大となる光周波数としてν₁，ν₂，……ν_Nを含む第１及び第２の二次光非線形媒質とを用い、
多波長入力信号光を直交する２つの偏波に分離し、そのうちの一方を前記第１の励起光源からの出力光の一部と合波して前記第１の二次光非線形媒質の一端へ入力し、他方を前記第１の励起光源からの出力光の一部と合波して前記第２の二次光非線形媒質の一端へ入力し、もしくは多波長入力信号光と前記第１の励起光源からの出力光とを合波するとともに直交する２つの偏波に分離し、そのうちの一方を前記第１の二次光非線形媒質の一端へ入力し、他方を前記第２の二次光非線形媒質の一端へ入力し、
前記第１の二次光非線形媒質の他端からの出力光と前記第２の励起光源からの出力光の一部とを合波して前記第２の二次光非線形媒質の他端へ入力し、前記第２の二次光非線形媒質の他端からの出力光と前記第２の励起光源からの出力光の一部とを合波して前記第１の二次光非線形媒質の他端へ入力する
ことを特徴とする多波長一括波長変換方法。 Respect integer of 2 or more N, any optical frequency _{_{_{2ν 1 -ν P1, 2ν 2 -ν}}} P1, ...... 2ν N arbitrary optical frequency -v _P1 multi-wavelength input signal light of each 2v ₁ -v _P2, 2ν ₂ −ν _P2 ............ Multiple wavelength batch wavelength conversion method for converting into 2ν _N −ν _P2 multi-wavelength converted light,
A first excitation light source having an optical frequency ν _P1 ;
A second excitation light source of optical frequency ν _P2 ;
Using first and second second-order nonlinear optical media including ν ₁ , ν ₂ ,... Ν _N as optical frequencies at which the second-harmonic light generation efficiency is maximized,
The multi-wavelength input signal light is separated into two orthogonally polarized waves, and one of them is combined with a part of the output light from the first pumping light source to one end of the first secondary optical nonlinear medium. The other is combined with a part of the output light from the first excitation light source and input to one end of the second secondary optical nonlinear medium, or the multi-wavelength input signal light and the first excitation The output light from the light source is multiplexed and separated into two orthogonal polarizations, one of which is input to one end of the first secondary optical nonlinear medium, and the other is input to the second secondary optical nonlinear Input to one end of the medium,
The output light from the other end of the first secondary light nonlinear medium and the part of the output light from the second excitation light source are combined and input to the other end of the second secondary light nonlinear medium. And combining the output light from the other end of the second secondary optical nonlinear medium and a part of the output light from the second pumping light source to combine the other end of the first secondary optical nonlinear medium. A multi-wavelength batch wavelength conversion method characterized by:

請求項１１記載の多波長一括波長変換方法において、
前記第１の二次光非線形媒質の他端からの出力光のうち光周波数２ν₁，２ν₂，……２ν_Nの光のみを前記第２の励起光源からの出力光の一部と合波して前記第２の二次光非線形媒質の他端へ入力し、前記第２の二次光非線形媒質の他端からの出力光のうち光周波数２ν₁，２ν₂，……２ν_Nの光のみを前記第２の励起光源からの出力光の一部と合波して前記第１の二次光非線形媒質の他端へ入力する
ことを特徴とする多波長一括波長変換方法。 In the multiple wavelength batch wavelength conversion method according to claim 11 ,
Of the output light from the other end of the first second-order nonlinear optical medium, only light with optical frequencies 2ν ₁ , 2ν ₂ ,... 2ν _N is combined with a part of the output light from the second excitation light source. And input to the other end of the second secondary optical nonlinear medium, and light having optical frequencies of 2ν ₁ , 2ν ₂ ,... 2ν _N out of the output light from the other end of the second secondary optical nonlinear medium. A multi-wavelength collective wavelength conversion method characterized in that only a part of the output light from the second excitation light source is combined and input to the other end of the first secondary nonlinear optical medium.

請求項１１または１２記載の多波長一括波長変換方法において、
伝搬方向に応じて光を２つの方路に分離する光非可逆回路を用いて、互いに逆方向に伝搬する多波長入力信号光と多波長変換光とを分離する
ことを特徴とする多波長一括波長変換方法。 The multi-wavelength batch wavelength conversion method according to claim 11 or 12 ,
A multi-wavelength batch characterized by separating multi-wavelength input signal light and multi-wavelength converted light propagating in opposite directions using an optical irreversible circuit that separates light into two paths according to the propagation direction Wavelength conversion method.

請求項８乃至１３いずれか記載の多波長一括波長変換方法において、
光周波数ν₁，ν₂，……ν_N付近にカットオフ光周波数を有する長波長帯透過フィルタ又は光周波数ν₁，ν₂，……ν_N付近にカットオフ光周波数を有する短波長帯透過フィルタを用いて、多波長変換光の出力光路から多波長変換光のみを取り出す
ことを特徴とする多波長一括波長変換方法。 The multi-wavelength batch wavelength conversion method according to any one of claims 8 to 13 ,
Optical wavelength ν ₁ , ν ₂ ,... Long wavelength band pass filter with cutoff optical frequency near ν _N or optical frequency ν ₁ , ν ₂ ,... Short wavelength band transmission with cutoff optical frequency near ν _N A multi-wavelength batch wavelength conversion method, wherein only a multi-wavelength converted light is extracted from an output optical path of the multi-wavelength converted light using a filter.