JPS61153616A - Polarization matching device - Google Patents
Polarization matching deviceInfo
- Publication number
- JPS61153616A JPS61153616A JP59274075A JP27407584A JPS61153616A JP S61153616 A JPS61153616 A JP S61153616A JP 59274075 A JP59274075 A JP 59274075A JP 27407584 A JP27407584 A JP 27407584A JP S61153616 A JPS61153616 A JP S61153616A
- Authority
- JP
- Japan
- Prior art keywords
- polarization
- light
- signal light
- local light
- optical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Mechanical Light Control Or Optical Switches (AREA)
- Optical Communication System (AREA)
Abstract
Description
【発明の詳細な説明】
（発明の技術分野）
本発明は、光ヘテロダインまたは光ホモダイン検波方式
を用いたコヒーレント光伝送方式における光偏波整合装
置の改善に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to an improvement of an optical polarization matching device in a coherent optical transmission system using an optical heterodyne or optical homodyne detection system.
（従来技術とその問題点）
近年、光波の振幅１位相１周波数及び偏波特性を利用し
たコヒーレント光伝送方式が注目を浴びている。このコ
ヒーレント光伝送方式では、光ヘテロダインあるいは光
ホモダイン検波方式を用いることにより、信号光ショッ
ト雑音限界の光検出が行えるため、従来の強度変調伝送
方式に比べて大幅な受信感度の改善が期待されている。(Prior Art and its Problems) In recent years, coherent optical transmission systems that utilize the amplitude, one phase, and one frequency of light waves and polarization characteristics have been attracting attention. This coherent optical transmission method uses optical heterodyne or optical homodyne detection to perform optical detection at the signal light shot noise limit, so it is expected to significantly improve reception sensitivity compared to conventional intensity modulation transmission methods. There is.
しかし、光ヘテロダイン検波方式及び光ホモダイン検波
方式で最大の受信効果を得るためには、局発光と信号光
の偏波面を整合させる必要がある。However, in order to obtain the maximum reception effect with the optical heterodyne detection method and the optical homodyne detection method, it is necessary to match the polarization planes of the local light and the signal light.
また、伝送媒体として通常の単一モード光ファイバ（以
下ｒＳＭＦＪと称す）を用いた場合、ＳＭＦの偏波特性
は外力や温度等の外部条件によって変化するため、偏波
面を一定に保持することは極めて困難である。従って、
光ヘテロダイン検波方式等を用いて検波する場合には、
局発光と信号光との偏波面を整合する回路が必要であり
、種々の検討がなされている。Furthermore, when using a normal single mode optical fiber (hereinafter referred to as rSMFJ) as a transmission medium, the polarization characteristics of the SMF change depending on external conditions such as external force and temperature, so it is necessary to maintain the plane of polarization constant. is extremely difficult. Therefore,
When detecting using optical heterodyne detection method etc.,
A circuit that matches the polarization planes of local light and signal light is required, and various studies have been made.
第１図は従来の偏波整合回路である（特開昭５６−１５
０７３１号）。第１図では局発光Ｅｔを信号光Ｅ。Figure 1 shows a conventional polarization matching circuit (Japanese Unexamined Patent Publication No. 56-15
No. 0731). In FIG. 1, the local light Et is the signal light E.
に合わせるため、まず信号光Ｅ、の偏光を表すだ円の長
軸を検出し、局発光側に挿入されたＡ波長板５の軸をこ
の長軸に一致させる。次に検波後のＤＣ出力が最大とな
るように２波長板６により局発光の直線偏光方向を回転
させる。以上により局発光ＥＬの偏光状態は信号光Ｅ、
に一致する。各部品の働きは次の通りである。信号光Ｅ
、は１０ｄＢ半透鏡１により一部を偏光方向検出のため
取り出され、検光子２を通過後受光器３により強度が測
定される。強度出力はサーボモータ４を制御し、強度出
力最大となる方向に検光子２を回転させる。In order to match this, first, the long axis of the ellipse representing the polarization of the signal light E is detected, and the axis of the A wavelength plate 5 inserted on the local light side is made to coincide with this long axis. Next, the linear polarization direction of the local light is rotated by the two-wavelength plate 6 so that the DC output after detection is maximized. From the above, the polarization state of the local light EL is signal light E,
matches. The function of each part is as follows. Signal light E
A part of the light is taken out by a 10 dB semi-transparent mirror 1 to detect the polarization direction, and after passing through an analyzer 2, the intensity is measured by a light receiver 3. The intensity output controls the servo motor 4 to rotate the analyzer 2 in the direction where the intensity output is maximum.
検光子２と局発光側のＡ波長板５は連動しており、信号
光Ｅ３の軸とＡ波長板５の軸は一致する。局発光Ｅｔは
２波長板６により偏光方向を自由に回転させられ、半透
鏡７により信号光Ｅ８と合波する。受光器８によるヘテ
ロダイン検波出力は各波長板６と連結したサーボモータ
９を制御する。The analyzer 2 and the A-wave plate 5 on the local light side are interlocked, and the axis of the signal light E3 and the axis of the A-wave plate 5 coincide. The polarization direction of the local light Et is freely rotated by the two-wavelength plate 6, and is combined with the signal light E8 by the semi-transparent mirror 7. The heterodyne detection output from the light receiver 8 controls a servo motor 9 connected to each wave plate 6.
このように、従来は信号光の偏波状態を検出して、直線
偏波で出力する局発光の偏波面をλ／２板６及びλ／４
板５で調整し、検出した信号光の偏波状態に合わせてい
た。In this way, conventionally, the polarization state of the signal light is detected and the polarization plane of the local light output as a linearly polarized wave is set using the λ/2 plate 6 and the λ/4 plate.
It was adjusted using the plate 5 to match the polarization state of the detected signal light.
しかし、この方式では信号光の偏波状態を検出するため
に、信号光を１０ｄＢ半透鏡ｌで分岐しなければならず
、伝送媒体で減衰を受けて弱い信号光に更に分岐損を与
えてしまっていた。However, in this method, in order to detect the polarization state of the signal light, the signal light must be split with a 10 dB semi-transparent mirror, which causes further branching loss to the weak signal light due to attenuation in the transmission medium. was.
従って、信号光の分岐損を防ぐために、第１図の１０ｄ
Ｂ半透鏡１からλ７４波長板５までを省略する構成もあ
るが、この場合には、信号光Ｅ１と局発光ＥＬとの偏波
状態を常に一致させることができず、偏波状態により損
失が必ず生じてしまう。すなわち、この構成では、信号
光Ｅ６の偏波状態に関係な（、局発光ＥＬが直線偏波と
なっているので、たまたま信号光Ｅ１が直線偏波で受信
される時は損失がなくなるが、それ以外は何ｄＢかの損
失となり、特に信号光Ｅ、が円偏波で受信した場合は３
ｄＢの損失を伴うことになるという欠点がある。Therefore, in order to prevent branching loss of signal light, 10d in FIG.
There is also a configuration in which the parts from the B semi-transparent mirror 1 to the λ74 wavelength plate 5 are omitted, but in this case, the polarization states of the signal light E1 and the local light EL cannot always be matched, and losses may occur depending on the polarization state. It will definitely happen. That is, in this configuration, there is no loss regardless of the polarization state of the signal light E6 (since the local light EL is a linearly polarized wave, if the signal light E1 happens to be received as a linearly polarized wave, there is no loss, but Otherwise, there will be a loss of some dB, especially if the signal light E is received as a circularly polarized wave, the loss will be 3 dB.
The disadvantage is that it involves a loss of dB.
以上のように、従来の方法では信号光Ｅ８に損失を与え
ることなく、かつ信号光Ｅ、と局発光ＥＬとの偏波面を
整合して検波出力を最大にすることはできなかった。As described above, in the conventional method, it was not possible to maximize the detection output without causing loss to the signal light E8 and by matching the polarization planes of the signal light E and the local light EL.
（発明の目的と特徴）
本発明は、上述した従来技術の欠点に鑑みなされたもの
で、信号光に損失を与えることはなく、信号光と局発光
との偏波面の整合をとり検波出力を常に最大となるよう
にすることのできる光偏波整合装置を提供することを目
的とする。(Objective and Features of the Invention) The present invention has been made in view of the above-mentioned drawbacks of the prior art, and the present invention matches the polarization planes of the signal light and the local light without causing loss to the signal light, and generates a detection output. It is an object of the present invention to provide an optical polarization matching device that can always maximize the polarization.
この目的達成のために、本発明の光偏波整合装置は、ビ
ームスプリッタまたは光カップラにより信号光と局発光
を合波する光へテロダイン検波または光ホモダイン検波
を用いたコヒーレント光伝送方式における偏波面の整合
装置において、信号光と局発光の少なくとも一方に直交
偏波モード間の相対位相差を調整するための手段と、偏
波面の主軸をそろえるための手段とを備えた偏波補償器
を有し、かつ検波の出力を分岐しビート成分を取り出す
バンドパス・フィルタとこのフィルタ出力のビート信号
レベルが常に最大となるように前記偏波補償器を制御す
るためのコントローラを具備し、前記信号光と前記局発
光の偏波面の整合をとることを特徴とする。In order to achieve this objective, the optical polarization matching device of the present invention has a polarization plane in a coherent optical transmission system using optical heterodyne detection or optical homodyne detection in which signal light and local light are combined using a beam splitter or an optical coupler. In the matching device, at least one of the signal light and the local light has a polarization compensator including means for adjusting the relative phase difference between orthogonal polarization modes and means for aligning the principal axes of the polarization planes. and a bandpass filter for branching the detection output to extract the beat component, and a controller for controlling the polarization compensator so that the beat signal level of the output of this filter is always at a maximum, The polarization planes of the local light and the local light are matched.
（発明の構成及び作用）
第２図は、局発光（ａ）と信号光（ｂ）の偏波面の座標
系を示したものである。図でｘ−ｙ（ξ−η）座標系は
、局発光偏波面の固定座標系を表し、ｘ’ −ｙ’（Ｉ
：−ブ）座標系は、信号光偏波面の座標系を表す。θは
局発光と信号光の偏波面の主軸（ξ−η軸）の相対角度
を表す。ここで、ＥＬ、Ｅ、を局発光及び信号光の電界
とすれば、それぞれの直交偏波成分は、次式で表される
。(Structure and operation of the invention) FIG. 2 shows the coordinate system of the polarization planes of the local light (a) and the signal light (b). In the figure, the x-y (ξ-η) coordinate system represents the fixed coordinate system of the local light polarization plane, and x'-y'(I
:-B) The coordinate system represents the coordinate system of the signal light polarization plane. θ represents the relative angle between the main axis (ξ−η axis) of the polarization plane of the local light and the signal light. Here, if EL and E are the electric fields of local light and signal light, their orthogonal polarization components are expressed by the following equations.
ｉ）局発光
但しω４．δ、はそれぞれ局発光の角周波数及び直交偏
波モード（ＩＥＬＸ、 ＩＥＬＦ）間の相対位相差を表
す。i) Local light ω4. δ represents the angular frequency of local light and the relative phase difference between orthogonal polarization modes (IELX, IELF), respectively.
ｉｉ ）儂ｉ人
ここで、ω８及びδ３は、信号光の角周波数及び直交偏
波モード（ＩＥ□′、１Ｅ□′）間の相対位相差を表し
、δ。は局発光と信号光の相対位相差を表す。ii) where ω8 and δ3 represent the angular frequency of the signal light and the relative phase difference between the orthogonal polarization modes (IE□′, 1E□′), and δ. represents the relative phase difference between the local light and the signal light.
式（２）の（ｘＩ−、／ ）座標系における信号光の電
界成分ＩＥ□／ 、 、、、′を局発光の固定座標系（
ｘ −ｙ）までθだけ座標変換すると、次式のようにな
る。The electric field component IE□/ , , , , of the signal light in the (xI-, / ) coordinate system of equation (2) is expressed as the fixed coordinate system of the local light (
When the coordinates are transformed by θ to x − y), the following equation is obtained.
式（２）を式（３）に代入すれば、
光検出器から放出される電流１（ｔ）は、次式で表され
る。By substituting equation (2) into equation (3), the current 1(t) emitted from the photodetector is expressed by the following equation.
ｉ （ｔ） ｏｃＶ（ｔ） Ｖ（ｔ）”但し、 ωミ
ω、−ωＬ （ビート角周波数）ここでは、信号光と局
発光のビート信号Ｈｔ）にのみ着目する。ビート信号の
正規化受光平均電力Ｉ（を戸は、次式で表される。i (t) ocV(t) V(t)" However, ωmiω, -ωL (beat angular frequency) Here, we will focus only on the beat signal Ht of the signal light and local light. Normalized light reception of the beat signal The average power I is expressed by the following formula.
ここで、Ｐ、 （・Ｅｌ”） 及びＰｔ、 （＝Ｅｔ
りは、それぞれ、信号光及び局発光の電力を表す。Here, P, (・El”) and Pt, (=Et
represents the power of the signal light and the local light, respectively.
（６）式から、ビート信号の正規化受光平均電力１（ｔ
）”が最大となる条件は
となる。すなわち、局発光と信号光との直交偏波モード
間の相対位相差が互いに等しく、かつ偏波面の主軸の相
対角度が等しいことを意味し、局発光と信号光との偏波
面の整合が取れれば良いことになる。From equation (6), the normalized received light average power 1(t
)" is the maximum. In other words, the relative phase difference between the orthogonal polarization modes of the local light and the signal light is equal to each other, and the relative angles of the principal axes of the polarization planes are the same. It is sufficient if the polarization planes of the signal light and the signal light can be matched.
即ち、本願発明はこの原理に基づき、常にビート信号の
受信レベルが最大となるように調整することによって、
局発光と信号光との偏波面の整合を図ったものである。That is, the present invention is based on this principle, and by adjusting so that the reception level of the beat signal is always at the maximum,
This is intended to match the polarization planes of local light and signal light.
（実施例１）
第３図は本発明による一実施例であり、１１は信号光Ｅ
、に局発光ＥＬを合成するためのビームスプリッタ−又
は１０ｄＢ半透鏡、１２は受光器であり、この受光器１
２でヘテロダイン検波し、その検波出力はビート角周波
数（ω＝ω、−ωＬ）の特性を有するバンドパス・フィ
ルタ（Ｂ、Ｐ、Ｆ）１７でビート成分を取り出し、１８
はそのピーク値をサーチ（トラッキング）するコントロ
ーラである。一方局発光（７）ＥＬは完全な直線偏波に
するために偏光子１５を通した後、前記コントローラ１
８の出力によって、直交偏波モード間の相対位相差を調
整するための位相補償器１４ （Ｂａｂｉｎｅｔ−５ｏ
ｌｅｉｌ−Ｃｏａ＋ｐｅｎｓａｔｏｒ：以下ｒＢＳＣＪ
と称す）と、同じくコントローラ１８の出力によって、
信号光Ｅ、と局発光Ｅ、の偏波面の主軸をそろえるため
のλ７２波長板１３とで制御され、ビームスプリンター
１１で信号光Ｅ８と合波される。(Embodiment 1) FIG. 3 shows an embodiment according to the present invention, and 11 is a signal light E.
, a beam splitter or a 10 dB semi-transparent mirror for combining the local light EL, 12 is a light receiver, and this light receiver 1
2 performs heterodyne detection, and the detected output is extracted with a band pass filter (B, P, F) 17 having characteristics of the beat angular frequency (ω=ω, -ωL), and the beat component is extracted at 18.
is a controller that searches (tracks) the peak value. On the other hand, the local light (7) EL is passed through a polarizer 15 to make it completely linearly polarized, and then passed through the controller 1.
A phase compensator 14 (Babinet-5o
leil-Coa+pensator: rBSCJ
) and also by the output of the controller 18,
It is controlled by a λ72 wavelength plate 13 for aligning the principal axes of the polarization planes of the signal light E and the local light E, and is combined with the signal light E8 by a beam splinter 11.
尚、以下ではＢＳＣ，１４（またはλ／４波長板を回転
して用いてもよい。）とλ／２波長板１３をまとめて偏
波補償器１６と称す。Note that, hereinafter, the BSC, 14 (or a λ/4 wavelength plate may be rotated and used) and the λ/2 wavelength plate 13 are collectively referred to as a polarization compensator 16.
次に動作について説明する。信号光Ｅ、が例えば第２図
中）の如く楕円偏波で受信した場合には、直線偏波の局
発光ＥＬを信号光Ｅ、と同一の楕円偏波にするためにＢ
ＳＣ，１４で直交偏波モード間の相対位相差（δ１−δ
Ｌ）を等しくすることによって局発光ＥＬを信号光Ｅ、
と同形の楕円偏波波にし、さらにλ／２波長板１３で楕
円偏波の長軸の角度（θ）を調整することによって、完
全に整合の取れた偏波面にすることがきる。なお、上記
のＢＳＣ。Next, the operation will be explained. When the signal light E is received as an elliptically polarized wave as shown in FIG.
SC, 14 determines the relative phase difference between orthogonal polarization modes (δ1−δ
By making L) equal, the local light EL becomes the signal light E,
By making the elliptically polarized wave the same shape as , and further adjusting the angle (θ) of the long axis of the elliptically polarized wave using the λ/2 wavelength plate 13, it is possible to obtain a completely matched polarization plane. In addition, the above BSC.
１４とλ／２波長板１３の制御は検波出力のビート信号
レベルが最大となるようにコントローラ１８で制御する
がまず最初にＢ５Ｃ６１４を制御し、次にλ／２波長板
１３を制御する。この動作過程を数回繰り返すことによ
り、偏波面の整合をとることができる。14 and the λ/2 wavelength plate 13 are controlled by the controller 18 so that the beat signal level of the detection output becomes maximum. First, the B5C 614 is controlled, and then the λ/2 wavelength plate 13 is controlled. By repeating this operation process several times, the polarization planes can be matched.
以上のように本願発明は信号光Ｅ、に損失を与えること
なく、信号光Ｅ、と局発光Ｅ、の偏波を整合することが
出来るので、常に最大検波効率を得ることが容易に実現
できる。As described above, the present invention can match the polarizations of the signal light E and the local light E without causing loss to the signal light E, so it is easy to always obtain the maximum detection efficiency. .
なお、局発光ＥＬの光源として通常半導体レーザを用い
るが、半導体レーザの出力は直線偏波となっているので
偏光子１５は省略しても良いことは言うまでもない。Note that although a semiconductor laser is normally used as a light source for local light EL, since the output of the semiconductor laser is a linearly polarized wave, it goes without saying that the polarizer 15 may be omitted.
（実施例２）
第４図は本発明による他の実施例であり、信号光Ｅ、の
偏波面を直線偏波に調整して局発光ＥＬの偏波面と整合
をとるものである。 １９ａは局発光ＥＬの偏波状態を
そのまま保持する偏波面保存光ファイバ、１９ｂは光フ
ァイバで領域Ａで局発光ＥＬと信号光Ｅ、を合波してい
る。２０は例えば圧電素子よりなり、第３図のＢＳＣ，
１４とほぼ同様の働きをするもので、コントローラ１８
の出力によって光ファイバ２０の表面への圧力を加減し
、信号光Ｅ、の屈折率変化をさせて偏波面を変えるもの
である。２１も圧電素子であるが、圧電素子２０と異な
る点は第５図に示す如り４５度の傾きに配置されている
ことである。圧電素子２１は第３図のλ／２波長板１３
とほぼ同様に信号光Ｅ、の主軸の傾きを調整するもので
ある。この圧電素子２０及び２１は検波出力後のビート
信号レベルが最大となるようにコントローラ１８で自動
制御される。すなわち、任意の偏波面で受信した信号光
Ｅ、は圧電素子２０及び２１によって直線偏波に変更さ
れ、通常の光ファイバ （Ｓ、Ｍ。(Embodiment 2) FIG. 4 shows another embodiment of the present invention, in which the polarization plane of the signal light E is adjusted to linear polarization to match the polarization plane of the local light EL. 19a is a polarization-maintaining optical fiber that maintains the polarization state of the local light EL, and 19b is an optical fiber that combines the local light EL and the signal light E in region A. 20 is made of a piezoelectric element, for example, and the BSC in FIG.
It functions almost the same as controller 14, and controller 18
The pressure on the surface of the optical fiber 20 is adjusted by the output of the signal light E, and the refractive index of the signal light E is changed to change the plane of polarization. 21 is also a piezoelectric element, but the difference from piezoelectric element 20 is that it is arranged at an angle of 45 degrees as shown in FIG. The piezoelectric element 21 is the λ/2 wavelength plate 13 in FIG.
This is to adjust the inclination of the main axis of the signal light E in almost the same way as the above. The piezoelectric elements 20 and 21 are automatically controlled by the controller 18 so that the beat signal level after detection output is maximized. That is, the signal light E, which is received with an arbitrary plane of polarization, is changed to linear polarization by the piezoelectric elements 20 and 21, and is transferred to a normal optical fiber (S, M).
Ｆ、） １９ｂと偏波面保存光ファイバ（Ｐ Ｍ Ｆ）
１９ａを用いたＳＭ −ＰＭ光ファイバカップラによっ
て直線偏波の局発光ＥＬと合波される。 ＳＭ−ＰＭ光
ファイバカップラはＰＭ −ＰＭ光ファイバカップラに
比べてＳＭＦのコアの楕円化による屈折率異方性が極め
て小さいため、ＰＭＦの主軸方向を考慮せずに容易に実
現できるという利点がある。なお、第３図と同一部分は
説明を省略する。F,) 19b and polarization maintaining optical fiber (PMF)
The light is combined with the linearly polarized local light EL by an SM-PM optical fiber coupler using the optical fiber 19a. Compared to the PM-PM optical fiber coupler, the SM-PM optical fiber coupler has an extremely small refractive index anisotropy due to the ovalization of the SMF core, so it has the advantage of being easily realized without considering the principal axis direction of the PMF. . Note that the description of the same parts as in FIG. 3 will be omitted.
本実施例では、光へテロダイン検波方式を例にとり説明
してきたが、光ホモダイン検波方式にも適用できること
は言うまでもない。Although this embodiment has been described using an optical heterodyne detection method as an example, it goes without saying that the present invention can also be applied to an optical homodyne detection method.
（発明の効果）
本発明は信号光Ｅ、の受信レベルに損失を与えることな
く、偏波整合ができるので、長距離光フアイバ伝送シス
テムに適用が可能であり、その効果は大である。(Effects of the Invention) Since the present invention can perform polarization matching without causing any loss to the reception level of the signal light E, it can be applied to long-distance optical fiber transmission systems, and its effects are significant.
第１図は従来の光偏波整合装置を示す配置系統図、第２
図は本発明の詳細な説明するための光偏波面の座標系図
、第３図及び第４図は本発明の実施例を示す配置系統図
、第５図は本発明による偏波補償器の圧電素子の配置関
係を説明するための略図である。
■・・・１０ｄＢ半透鏡、 ２・・・検光子、 ３．８
・・・受光器、 ４．９・・・サーボモータ、 ５・・
・Ａ波長板、６．１３・・・〃波長板、 ７・・・半透
鏡、 １１・・・ビームスプリッタ−１１２・・・受光
器、 １４・・・位相補償器（Ｂ、 Ｓ、 Ｃ，）、
１５・・・偏光子、 １６・・・偏波補償器、１７・・
・バンドパス・フィルタ、１８・・・コントローラ、
１９ａ・・・偏波面保存光ファイバ、１９ｂ・・・光フ
ァイバ、 ２０．２１・・・圧電素子。Figure 1 is a layout diagram showing a conventional optical polarization matching device;
The figure is a coordinate system diagram of an optical polarization plane for explaining the present invention in detail, Figures 3 and 4 are arrangement diagrams showing an embodiment of the present invention, and Figure 5 is a piezoelectric polarization compensator according to the present invention. It is a schematic diagram for explaining the arrangement relationship of elements. ■...10dB semi-transparent mirror, 2...analyzer, 3.8
...Receiver, 4.9...Servo motor, 5...
・A wavelength plate, 6.13...Wave plate, 7...Semi-transparent mirror, 11...Beam splitter-112...Photodetector, 14...Phase compensator (B, S, C, ),
15...Polarizer, 16...Polarization compensator, 17...
・Bandpass filter, 18...controller,
19a...Polarization maintaining optical fiber, 19b...Optical fiber, 20.21...Piezoelectric element.
Claims (1)
を合波する光ヘテロダイン検波または光ホモダイン検波
を用いたコヒーレント光伝送方式における偏波面の整合
装置において、該信号光と該局発光の少なくとも一方に
直交偏波モード間の相対位相差を調整するための手段と
偏波面の主軸をそろえるための手段とを備えた偏波補償
器を有し、かつ前記検波の出力を分岐しビート成分を取
り出すバンドパス・フィルタと、該フィルタの出力のビ
ート信号レベルが常に最大となるように前記偏波補償器
を制御するためのコントローラを具備し、前記信号光と
前記局発光の偏波面の整合をとるように構成されたこと
を特徴とする光偏波整合装置。In a polarization plane matching device in a coherent optical transmission system using optical heterodyne detection or optical homodyne detection in which a signal and local light are combined using a beam splitter or an optical coupler, at least one of the signal light and the local light has orthogonal polarization. A bandpass filter that has a polarization compensator equipped with a means for adjusting the relative phase difference between modes and a means for aligning the principal axes of the plane of polarization, and branches the output of the detection to extract the beat component. and a controller for controlling the polarization compensator so that the beat signal level of the output of the filter is always at a maximum, and configured to match the polarization planes of the signal light and the local light. An optical polarization matching device characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59274075A JPS61153616A (en) | 1984-12-27 | 1984-12-27 | Polarization matching device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59274075A JPS61153616A (en) | 1984-12-27 | 1984-12-27 | Polarization matching device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS61153616A true JPS61153616A (en) | 1986-07-12 |
Family
ID=17536622
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59274075A Pending JPS61153616A (en) | 1984-12-27 | 1984-12-27 | Polarization matching device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61153616A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6370623A (en) * | 1986-09-09 | 1988-03-30 | アルカテル・エヌ・ブイ | Photoheterodyne receiver |
| CN110544875A (en) * | 2019-09-09 | 2019-12-06 | 衢州职业技术学院 | Optical modulation device and method of vertical cavity surface laser with grating |
| WO2020050299A1 (en) * | 2018-09-07 | 2020-03-12 | 日本電気株式会社 | Optical reception device and reception method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56150731A (en) * | 1980-04-23 | 1981-11-21 | Nippon Telegr & Teleph Corp <Ntt> | Optical polarization matching and combining device |
| JPS60121424A (en) * | 1983-12-05 | 1985-06-28 | Nippon Telegr & Teleph Corp <Ntt> | Optical receiver |
-
1984
- 1984-12-27 JP JP59274075A patent/JPS61153616A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56150731A (en) * | 1980-04-23 | 1981-11-21 | Nippon Telegr & Teleph Corp <Ntt> | Optical polarization matching and combining device |
| JPS60121424A (en) * | 1983-12-05 | 1985-06-28 | Nippon Telegr & Teleph Corp <Ntt> | Optical receiver |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6370623A (en) * | 1986-09-09 | 1988-03-30 | アルカテル・エヌ・ブイ | Photoheterodyne receiver |
| WO2020050299A1 (en) * | 2018-09-07 | 2020-03-12 | 日本電気株式会社 | Optical reception device and reception method |
| JPWO2020050299A1 (en) * | 2018-09-07 | 2021-08-30 | 日本電気株式会社 | Optical receiver and receiving method |
| US11621783B2 (en) | 2018-09-07 | 2023-04-04 | Nec Corporation | Optical receiver and receiving method |
| CN110544875A (en) * | 2019-09-09 | 2019-12-06 | 衢州职业技术学院 | Optical modulation device and method of vertical cavity surface laser with grating |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4755027A (en) | Method and device for polarizing light radiation | |
| US5712704A (en) | Appliance for measuring polarization mode dispersion and corresponding measuring process | |
| US5903393A (en) | Optical-hybrid etalons for simultaneous phase- and polarization-diversity operations | |
| US5003625A (en) | Optical heterodyne detection and integrated optical component suitable for use in such a device | |
| CN109724584A (en) | Light source relative intensity noise offsets structure in a kind of fibre optic gyroscope | |
| JPH0572777B2 (en) | ||
| JPS61153616A (en) | Polarization matching device | |
| CA2028647C (en) | Method and means for the transmission of an electromagnetic signal in an optical fibre | |
| JPS5928116A (en) | Photocoupler | |
| JPS58196416A (en) | Optical fiber laser gyroscope | |
| JPH0222503A (en) | Laser interference measuring instrument | |
| JPH07281229A (en) | Optical polarization controller | |
| JPH01108534A (en) | Optical type heterodyne or homodyne detector for optical signal beam | |
| US7206465B2 (en) | All-fiber linear design depolarizer for all-states of polarization | |
| JPH04138331A (en) | Optical pulse tester using heterodyne light receiving | |
| JPS6148715A (en) | Optical fiber gyro | |
| JPH0418493B2 (en) | ||
| WO1993005554A1 (en) | A method of suppressing relative intensity noise in coherent optical systems, such as communication receivers | |
| JPH1117262A (en) | High wavelength precision laser light source | |
| JPH0114567B2 (en) | ||
| JP2507790B2 (en) | Semiconductor laser FM modulation characteristic measuring device | |
| JPH02236102A (en) | Laser interferometer | |
| JPS6344171B2 (en) | ||
| JP2985487B2 (en) | Light wave interferometer | |
| JPH022532A (en) | Optical amplifying module |