JPH05241217A - Second harmonic wave generating element - Google Patents
Second harmonic wave generating elementInfo
- Publication number
- JPH05241217A JPH05241217A JP7848392A JP7848392A JPH05241217A JP H05241217 A JPH05241217 A JP H05241217A JP 7848392 A JP7848392 A JP 7848392A JP 7848392 A JP7848392 A JP 7848392A JP H05241217 A JPH05241217 A JP H05241217A
- Authority
- JP
- Japan
- Prior art keywords
- lattice
- crystal
- polarization inversion
- domain
- heat treatment
- 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
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/35—Non-linear optics
- G02F1/355—Non-linear optics characterised by the materials used
- G02F1/3558—Poled materials, e.g. with periodic poling; Fabrication of domain inverted structures, e.g. for quasi-phase-matching [QPM]
Landscapes
- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は非線形強誘電体光学材料
であるＬｉＴａＯ3やＬｉＮｂＯ3結晶を用いた第２高調
波発生素子（以下ＳＨＧ素子）におけるＳＨＧ素子の高
効率化に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high efficiency SHG element in a second harmonic generation element (hereinafter referred to as SHG element) using a LiTaO 3 or LiNbO 3 crystal which is a nonlinear ferroelectric optical material.
【０００２】[0002]
【従来の技術】近年、小型軽量の青色光源として、波長
８３０ｎｍの半導体レーザを導波路型のＳＨＧ素子で半
分の波長４１５ｎｍの青色の光に変換することが注目さ
れている。例えば特開昭６１−１８９３４公報に記載さ
れているようにＬｉＮｂＯ3結晶上にプロトン交換法
（ＬｉＮｂＯ3のＬｉイオンとプロトンを一部置換して
光導波路を形成する方法）により光導波路を形成し、上
記光導波路の一端に基本波を入射し、チェレンコフ放射
によりＳＨＧ光を発生させることが提案させている。こ
れを図２に示す。さらに最近では例えばElectronics Le
tters,25,11（１９８９年）の第７３１〜７３２頁で論
じられているように、分極反転を用いて位相整合を行う
方法が提案された。すなわち図３に示すようにＬｉＮｂ
Ｏ3結晶上にＴｉ拡散によって周期格子を作製し、約１
１００℃に加熱して周期格子層だけの分極を反転させ、
その後プロトン交換法によって光導波路を作製し、基本
波を入射しＳＨＧ光を取り出すものである。ＬｉＴａＯ
3結晶を用いる場合には例えばAppl.Phys.Lett.58(24)
（１９９１年）第２７３２〜２７３４頁で論じられてい
るようにＴｉ拡散の替わりにプロトン交換法によって周
期格子を作製し、約６００℃に加熱し周期格子層だけ分
極を反転させ、さらにプロトン交換法によって光導波路
を作製する方法も試みられている。これを図４に示す。
またIEEE J.QuantumElectron.,vol.QE-24（１９８８
年）の第９１３〜９１９頁で論じられているように共振
器内に非線形結晶であるＬｉＮｂＯ3を挿入し、角度お
よび温度整合によりＳＨＧ光を得る方法も試みられてい
る。これを図６に示す。2. Description of the Related Art Recently, as a compact and lightweight blue light source, attention has been paid to converting a semiconductor laser having a wavelength of 830 nm into blue light having a wavelength of 415 nm, which is half that of a semiconductor laser. For example, as described in JP-A-61-18934, an optical waveguide is formed on a LiNbO 3 crystal by a proton exchange method (a method of partially replacing Li ions and protons of LiNbO 3 to form an optical waveguide). It is proposed that the fundamental wave be incident on one end of the optical waveguide and SHG light be generated by Cherenkov radiation. This is shown in FIG. More recently, for example, Electronics Le
As discussed in Tters, 25, 11 (1989), pages 731-732, a method of performing phase matching using polarization reversal has been proposed. That is, as shown in FIG.
O 3 to produce a periodic grating by Ti diffusion on the crystal, about 1
It is heated to 100 ℃ and the polarization of the periodic lattice layer is reversed.
After that, an optical waveguide is produced by the proton exchange method, and the fundamental wave is incident to take out SHG light. LiTaO
When using 3 crystals, for example, Appl.Phys.Lett.58 (24)
(1991) As discussed on pages 2732 to 2734, a periodic lattice was prepared by a proton exchange method instead of Ti diffusion, heated to about 600 ° C. to invert the polarization of only the periodic lattice layer, and further the proton exchange method. A method of manufacturing an optical waveguide has also been attempted. This is shown in FIG.
IEEE J. Quantum Electron., Vol. QE-24 (1988)
(1993), pages 913 to 919, a method of obtaining SHG light by angle and temperature matching by inserting LiNbO 3 which is a non-linear crystal in a resonator has been attempted. This is shown in FIG.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、上記従
来技術には、次に示すような問題点があった。図２に示
すチェレンコフ放射を用いる方法では２２に示すように
発生するＳＨＧ光のビーム形状が三日月型となり、極め
て波面収差が大きく、これを回折限界まで絞り込むこと
はほとんど不可能である。上記例に対して新しく提案さ
れた図３、４に示す分極反転を用いて位相整合を行う方
法はＳＨＧ光がコリメートされた光であるため、チェレ
ンコフ放射光と比較して集光が極めて容易であるという
利点を持つ。しかし、分極反転格子の断面形状が、Ｔｉ
拡散法で形成されたものは３１に示すように三角形であ
り、プロトン交換法では４１に示すように半円形である
ため、理想的な矩型断面の分極反転格子を持つＳＨＧ素
子本来の効率でＳＨＧ光を発生できていない。図６で示
す構成において結晶２１の両端面は放物線ミラー加工さ
れており、１３の内面による全反射によりモノリシック
リング共振器を形成している。ＬｉＮｂＯ3結晶２１内
で実線で表される光路内で位相整合によりＳＨＧ光１７
を得るものである。この構造ではバルク結晶の常光と異
常光の屈折率分散の差を利用するもので非線形光学係数
のｄ31を用い、最も大きなｄ33を用いることができず、
ＬｉＮｂＯ3結晶２１を用いた場合、青色ＳＨＧ光では
なく緑色ＳＨＧしか得られない。また、温度許容幅が
０．７℃・ｃｍと非常に小さく１０７℃の高温で位相整
合させるためヒーター２２内に納めることが必要である
こと等が問題である。 本発明の目的は周期的な面状の
分極反転格子結晶をモノリシックリング共振器とするこ
とで青色ＳＨＧを高効率で得られるＳＨＧ素子を実現す
ることにある。However, the above-mentioned prior art has the following problems. In the method using Cherenkov radiation shown in FIG. 2, the beam shape of the SHG light generated as shown by 22 is crescent-shaped, and the wavefront aberration is extremely large, and it is almost impossible to narrow it down to the diffraction limit. The method for performing phase matching using polarization reversal shown in FIGS. 3 and 4 newly proposed for the above example is light in which SHG light is collimated, and therefore it is extremely easy to collect light as compared with Cherenkov radiation. Has the advantage of being. However, the cross-sectional shape of the domain-inverted lattice is Ti
Since the one formed by the diffusion method is triangular as shown by 31 and the semicircle as shown by 41 by the proton exchange method, the SHG element having the ideal polarization reversal grating of the rectangular cross section has the original efficiency. SHG light cannot be generated. In the structure shown in FIG. 6, both end surfaces of the crystal 21 are parabolic mirror processed, and a total reflection by the inner surface of 13 forms a monolithic ring resonator. In the LiNbO 3 crystal 21, the SHG light 17 is generated by phase matching in the optical path represented by the solid line.
Is what you get. In this structure, the difference in refractive index dispersion between the ordinary light and the extraordinary light of the bulk crystal is used, and the non-linear optical coefficient d 31 is used, and the largest d 33 cannot be used.
When the LiNbO 3 crystal 21 is used, only green SHG is obtained instead of blue SHG light. Further, there is a problem in that the temperature allowable width is as very small as 0.7 ° C. · cm and it is necessary to store it in the heater 22 for phase matching at a high temperature of 107 ° C. An object of the present invention is to realize an SHG element that can obtain blue SHG with high efficiency by using a periodic plane-shaped domain-inverted lattice crystal as a monolithic ring resonator.
【０００４】[0004]
【課題を解決するための手段】本発明の目的は図１に示
すように周期的に面状の分極反転格子結晶を用いモノリ
シックリング共振器を形成することで高効率の青色ＳＨ
Ｇ光を発生させることにある。ＬｉＴａＯ3またはＬｉ
ＮｂＯ3結晶におけるスパイク状分域の存在は、例えば
J.Appl.Phys.vol.46,No.3（１９７５年）の１０６３頁
に見られるように良く知られていたが、これまでスパイ
ク状分域を制御する手段はなかった。本発明はこのスパ
イク状分域の生成を人為的に制御することで、結晶のｃ
軸方向に垂直に延びる性質を利用して、高効率ＳＨＧ素
子を達成するというものである。そこで我々はスパイク
状分域領域が出現する条件について検討したところ、Ｌ
ｉＴａＯ3またはＬｉＮｂＯ3結晶が比較的急速な熱履歴
を受けたときにスパイク状分域領域が多く出現すること
を見いだした。このことは急速な熱変化に対応して分極
の大きさが急激に変化し、そのため分域壁周辺に実効的
な電界が発生するためであり、このためスパイク状分域
が分極の方向であるｃ軸に沿って成長するものと考えら
れる。このため同様の現象は熱変化だけでなく例えば応
力によってもスパイク状分域を生成できる可能性がある
と考えられる。もし分域の芽を周期的に形成すれば、こ
のスパイク状分域を周期的に配置することができると考
えるに至った。分域の芽としては、局所的に分極の大き
さあるいはその向きが周辺部分と異なった領域が分域の
芽となりうる可能性があると考えられる。以上の考えに
基づき、ＬｉＴａＯ3またはＬｉＮｂＯ3結晶に面状の周
期的スパイク状分極反転格子を形成するために、結晶表
面に周期的な格子パタ−ンを形成後、適当な昇降温速度
で熱処理を行い周期的なスパイク状の分極反転格子を発
現せしめ、それを用いてモノリシックリング共振器を形
成することで高効率のＳＨＧ素子を実現できると考え
た。また分極反転格子の幅は使用する光の波長によって
選ばれるがほぼ１μｍ以上１０μｍ以下の範囲で表面に
形成した分域の芽領域の幅とほぼ等しくすることにより
望ましい矩型状の分極反転格子が実現できる。前記スパ
イク状分極反転格子は結晶表面より内部方向に形成さ
れ、その先端が単一ないし複数のスパイクの集まりで、
また深さが結晶の厚さより小さく位相整合する部分以外
には分極反転格子がないことを特徴としている。The object of the present invention is to provide a highly efficient blue SH by forming a monolithic ring resonator using periodically plane-inverted lattice crystals as shown in FIG.
G light is generated. LiTaO 3 or Li
The existence of spike domains in NbO 3 crystals is
As is well known, as seen on page 1063 of J. Appl. Phys. Vol. 46, No. 3 (1975), there has been no means to control spike-shaped domains. The present invention artificially controls the generation of this spike-shaped domain, and
A high-efficiency SHG element is achieved by utilizing the property of extending perpendicularly to the axial direction. Therefore, we examined the conditions under which the spike-shaped domain region appears and found that L
It has been found that many spike-like domain regions appear when the iTaO 3 or LiNbO 3 crystal undergoes a relatively rapid thermal history. This is because the magnitude of polarization changes abruptly in response to a rapid thermal change, and an effective electric field is generated around the domain wall. Therefore, the spike domain is the direction of polarization. It is considered to grow along the c-axis. Therefore, it is considered that the same phenomenon may possibly generate spike-like domains not only due to thermal change but also due to stress, for example. We have come to think that this spike-shaped domain can be arranged periodically if the domain buds are formed periodically. It is conceivable that the bud of the domain may be a bud of the domain in which the magnitude or direction of polarization locally differs from that of the peripheral portion. Based on the above idea, in order to form a plane periodic spike-shaped polarization inversion lattice in the LiTaO 3 or LiNbO 3 crystal, after forming a periodic lattice pattern on the crystal surface, heat treatment at an appropriate temperature rising / falling rate. It was thought that a highly efficient SHG element could be realized by performing a periodical spike-shaped polarization inversion grating and forming a monolithic ring resonator using it. The width of the polarization inversion grating is selected according to the wavelength of the light to be used, but by making it approximately equal to the width of the bud region of the domain formed on the surface in the range of approximately 1 μm or more and 10 μm or less, a desirable rectangular polarization inversion grating can be obtained. realizable. The spike-shaped polarization inversion lattice is formed inward from the crystal surface, and its tip is a collection of a single or a plurality of spikes,
Further, it is characterized in that there is no domain-inverted lattice other than the portion where the depth is smaller than the crystal thickness and the phase is matched.
【０００５】[0005]
【実施例】以下、本発明の実施例について詳しく説明す
る。図１は本発明によるＳＨＧ素子の実施例を示す構成
および動作説明図、図５（ａ）〜（ｇ）は上記ＳＨＧ素
子の製造工程を示す図である。図７はスパイク状分極反
転格子を示す写真である。図１において、１１は表面が
−ｃ面であるＬｉＴａＯ3単結晶基板で自発分極の向き
は下向きである。１２は分極がスパイク状に反転された
部分で、この部分では分極の向きは上向きである。M.Di
domenico Jr.らの文献 Journal of Applied Physics Vo
l.40, No.2 ７２０〜７３４頁によると非線形光学係数
の符号はＬｉＮｂＯ3またはＬｉＴａＯ3等の空間群Ｒ３
ｃの強誘電体結晶の場合自発分極の向きと一致する。従
って、本実施例の結晶の非線形光学係数ｄ33も周期的に
反転されているといえる。この構成において結晶１１の
両端面は放物線ミラー加工されており、１３の内面によ
る全反射によりモノリシックリング共振器を形成してい
る。結晶１１内で実線で表される光路内で位相整合によ
りＳＨＧ光１７を得るものである。この構成においてＳ
ＨＧ出射側ミラー１６の表面は基本波を反射しＳＨＧ光
は透過する誘電体多層膜を形成している。１４は入射基
本波で結晶表面に垂直方向に偏光している。１５は結晶
内部で発生したＳＨＧ光であり結晶表面に垂直な方向に
偏光している。次に、本発明の分極反転格子の形成方法
を図５を用いて説明する。図５（ａ）に示すようにＬｉ
ＴａＯ3結晶の−Ｚ（ｃ）面を使用するレーザ光波長λ
の１／１０程度まで研磨した結晶１１を用意する。
（ｂ）１１の−Ｚ面上にＴａ膜５１を３０ｎｍスパッタ
リングで成膜する。（ｃ）５１膜上にホトレジスト５２
をスピンコートし、分極反転１２を行う部分が窓あけさ
れたホトマスクを用い、通常のホトリソグラフィ技術に
よりホトレジスト５２のパターニングを行った。ホトマ
スクのパタ−ン周期は１〜１０μｍで発生させるＳＨＧ
光の周期に合わせてある。（ｄ）パターニングしたホト
レジスト５２をマスクとして、ＣＦ3Ｃｌガスを用いた
ＲＩＥによるドライエッチングにより、Ｔａ膜５１をパ
ターニングする。（ｅ）ホトレジスト５２をアセトンに
より除去し、ピロ燐酸を用いてプロトン交換を２６０
℃、３０〜６０分で行うことで、５３のプロトン交換層
が形成される。（ｆ）Ｔａ膜５１をＮａＯＨの水溶液で
エッチングする。（ｇ）上記５３のプロトン交換層が形
成された結晶を電気炉に挿入し、熱処理を行うことでス
パイク状分極反転層１２を形成させる。熱処理条件は温
度５４０℃で保持時間０．５分、熱処理温度までの昇温
速度を５０℃／分以上で行い、熱処理温度からの降温速
度を５０℃／分以上で行うことによりスパイク状分極反
転格子１２が作製できた。その深さは結晶表面に形成さ
れるプロトン交換格子パタ−ン深さより大きく結晶厚さ
より小さかった。またその幅はプロトン交換パタ−ンの
幅とほぼ等しい。この結晶の両端面を放物線ミラー加工
する事でモノリシックリング共振器が形成される。図７
は作製されたスパイク状分極反転格子の断面写真であ
る。以上示した作製方法で面状スパイク分極反転格子を
作製し、光の入射端面を放物線ミラー研磨し、素子長１
０ｍｍのモノリシックリング共振器ＳＨＧ素子を作製し
た。作製したＳＨＧ素子に波長８３０ｎｍの基本波を入
射したところ、４１５ｎｍの青色ＳＨＧ光が得られた。
この時のＳＨＧ光出力は０．５ｍＷであり、ＳＨＧ効率
は５％であった。このことにより、面状スパイク分極反
転格子を用いることが高効率のＳＨＧ素子に有用である
ことが分かった。EXAMPLES Examples of the present invention will be described in detail below. FIG. 1 is a configuration and operation explanatory view showing an embodiment of an SHG element according to the present invention, and FIGS. 5A to 5G are views showing a manufacturing process of the SHG element. FIG. 7 is a photograph showing a spike-shaped polarization inversion grating. In FIG. 1, 11 is a LiTaO 3 single crystal substrate whose surface is the −c plane, and the direction of spontaneous polarization is downward. Reference numeral 12 is a portion where the polarization is inverted in a spike shape, and the polarization direction is upward in this portion. M.Di
Domenico Jr. et al. Journal of Applied Physics Vo
L.40, according to the No.2, pages 720-734 sign of the nonlinear optical coefficient is LiNbO 3 or LiTaO 3 or the like space group R3
In the case of the ferroelectric crystal of c, it coincides with the direction of spontaneous polarization. Therefore, it can be said that the nonlinear optical coefficient d 33 of the crystal of this example is also periodically inverted. In this structure, both end surfaces of the crystal 11 are parabolic mirror processed, and a total reflection by the inner surface of 13 forms a monolithic ring resonator. The SHG light 17 is obtained by phase matching in the optical path represented by the solid line in the crystal 11. S in this configuration
The surface of the HG emission side mirror 16 forms a dielectric multilayer film that reflects the fundamental wave and transmits the SHG light. The incident fundamental wave 14 is polarized in the direction perpendicular to the crystal surface. Reference numeral 15 denotes SHG light generated inside the crystal, which is polarized in a direction perpendicular to the crystal surface. Next, a method for forming a domain-inverted grating according to the present invention will be described with reference to FIG. As shown in FIG.
Laser light wavelength λ using −Z (c) plane of TaO 3 crystal
The crystal 11 polished to about 1/10 is prepared.
(B) A Ta film 51 is formed on the −Z plane of 11 by sputtering with a thickness of 30 nm. (C) 51 photoresist 52 on the film
Was spin-coated, and the photoresist 52 was patterned by a normal photolithography technique using a photomask in which a portion where the polarization inversion 12 was performed was opened. SHG generated with a photomask pattern period of 1 to 10 μm
Matched to the light cycle. (D) Using the patterned photoresist 52 as a mask, the Ta film 51 is patterned by dry etching by RIE using CF 3 Cl gas. (E) The photoresist 52 is removed with acetone, and the proton exchange is performed 260 using pyrophosphoric acid.
The proton exchange layer of 53 is formed by performing the treatment at 30 ° C. for 30 to 60 minutes. (F) The Ta film 51 is etched with an aqueous solution of NaOH. (G) The crystal in which the proton exchange layer of 53 is formed is inserted into an electric furnace and heat-treated to form the spike-shaped polarization inversion layer 12. The heat treatment conditions are a temperature of 540 ° C., a holding time of 0.5 minutes, a temperature rising rate up to the heat treatment temperature of 50 ° C./min or more, and a temperature lowering rate from the heat treatment temperature of 50 ° C./min or more to cause spike-like polarization reversal. The lattice 12 was produced. The depth was larger than the depth of the proton exchange lattice pattern formed on the crystal surface and smaller than the crystal thickness. Its width is almost equal to that of the proton exchange pattern. A monolithic ring resonator is formed by processing both end faces of this crystal with a parabolic mirror. Figure 7
[Fig. 3] is a cross-sectional photograph of the produced spike-shaped polarization inversion grating. A planar spike polarization-inverted grating was prepared by the above-described manufacturing method, the light incident end face was polished by a parabolic mirror, and the device length was set to 1
A 0 mm monolithic ring resonator SHG element was produced. When a fundamental wave having a wavelength of 830 nm was incident on the manufactured SHG element, blue SHG light of 415 nm was obtained.
At this time, the SHG light output was 0.5 mW and the SHG efficiency was 5%. From this, it was found that the use of the plane spike polarization inversion grating is useful for a highly efficient SHG element.
【０００６】[0006]
【発明の効果】以上の説明から明らかなように、本発明
によれば、周期的な面状スパイク分極反転格子を用いた
結晶をモノリシックリング共振器に用いることで青色Ｓ
ＨＧを高効率で得られるＳＨＧ素子が実現できた。As is apparent from the above description, according to the present invention, a blue S is obtained by using a crystal using a periodic plane spike polarization inversion grating in a monolithic ring resonator.
The SHG element which can obtain HG with high efficiency was realized.
【図１】本発明の実施例を説明するための構造図であ
る。FIG. 1 is a structural diagram for explaining an embodiment of the present invention.
【図２】チェレンコフ輻射を用いた従来のＳＨＧ素子を
示す図である。FIG. 2 is a diagram showing a conventional SHG element using Cherenkov radiation.
【図３】三角形状の分極反転格子を用いた従来のＳＨＧ
素子を示す図である。FIG. 3 is a conventional SHG using a triangular polarization inversion grating.
It is a figure which shows an element.
【図４】半円状の分極反転格子を用いた従来のＳＨＧ素
子を示す図である。FIG. 4 is a diagram showing a conventional SHG element using a semicircular polarization inversion grating.
【図５】（ａ）〜（ｇ）はそれぞれ本発明に係る面状ス
パイク分極反転格子の作製方法を示す図である。5 (a) to 5 (g) are diagrams showing a method of manufacturing the planar spike polarization inversion grating according to the present invention.
【図６】ＬｉＮｂＯ3を用いた従来のモノリシックリン
グ共振器ＳＨＧ素子を示す図である。FIG. 6 is a diagram showing a conventional monolithic ring resonator SHG element using LiNbO 3 .
【図７】スパイク状分極反転格子を示す金属組織写真で
ある。FIG. 7 is a photograph of a metal structure showing a spike-shaped polarization inversion lattice.
１１ 結晶（ＬｉＴａＯ3） １２ 面状スパイク分極反転領域 １３ 全反射ミラー １４ 基本波 １５ ＳＨＧ出力光 １６ 誘電体多層膜 ２１ 結晶（ＬｉＮｂＯ3） ２２ チェレンコフＳＨＧ光 ２３ 光導波路 ３１ 三角状分極反転領域 ４１ 半円状分極反転領域 ５１ Ｔａ膜 ５２ ホトレジスト ５３ プロトン交換領域 ６１ ヒーター11 crystal (LiTaO 3 ) 12 planar spike polarization inversion region 13 total reflection mirror 14 fundamental wave 15 SHG output light 16 dielectric multilayer film 21 crystal (LiNbO 3 ) 22 Cerenkov SHG light 23 optical waveguide 31 triangular polarization inversion region 41 half Circular polarization inversion region 51 Ta film 52 Photoresist 53 Proton exchange region 61 Heater
Claims (13)
期的な面状の分極反転領域を形成した分極反転格子結晶
を用いることを特徴とする第２高調波発生素子。1. A second harmonic generation device comprising a polarization inversion lattice crystal in which a periodic plane polarization inversion region is formed in a LiTaO 3 or LiNbO 3 crystal.
とするモノリシックリング共振器を形成して第２高調波
を発生させることを特徴とする請求項１の第２高調波発
生素子。2. A second harmonic generation element according to claim 1, wherein a monolithic ring resonator having mirrors on both end faces of the polarization inversion lattice crystal is formed to generate a second harmonic.
ないし小さいことを特徴とする請求項１ないし２の分極
反転格子結晶を用いた第２高調波発生素子。3. The second harmonic generation element using a polarization inversion lattice crystal according to claim 1, wherein the width of the polarization inversion region is equal to or smaller than the width of the crystal.
一ないし複数のスパイク状の尖った形状を持つことを特
徴とする請求項１ないし３の分極反転格子結晶を用いた
第２高調波発生素子。4. The second harmonic using the domain-inverted lattice crystal according to claim 1, wherein a tip of the domain-inverted region in the depth direction has a single or a plurality of spike-like sharp points. Wave generating element.
ｍ以上１０μｍ以下であることを特徴とする請求項１な
いし４の分極反転格子結晶を用いた第２高調波発生素
子。5. The width of the domain-inverted region in the periodic direction is 1 μm.
The second harmonic generation element using the domain-inverted lattice crystal according to any one of claims 1 to 4, wherein the second harmonic generation element has a thickness of m or more and 10 µm or less.
の幅より大きいことを特徴とする請求項１ないし５の分
極反転格子結晶を用いた第２高調波発生素子。6. The second harmonic generation element using a polarization inversion lattice crystal according to claim 1, wherein the polarization inversion region has a depth larger than a width in the periodic direction.
れることを特徴とする請求項１ないし６の分極反転格子
結晶を用いた第２高調波発生素子。7. The second harmonic generation device using a polarization inversion lattice crystal according to claim 1, wherein the polarization inversion region is formed by heat treatment.
処理温度からの降温時の一方または両方に５０℃／分以
上の温度変化速度を含むことを特徴とする請求項７の分
極反転格子結晶を用いた第２高調波発生素子。8. The polarization inversion lattice crystal according to claim 7, wherein a temperature change rate of 50 ° C./min or more is included in one or both of the temperature rising to the heat treatment temperature and the temperature decrease from the heat treatment temperature. Second harmonic generator used.
パタ−ンを形成し、その格子パターンと周期が一致した
周期を持つ分極反転領域を形成することを特徴とする請
求項１ないし８の分極反転格子結晶を用いた第２高調波
発生素子。9. A domain inversion region is formed on the crystal surface as a nucleus of domain inversion, and a domain inversion region having a period which coincides with the lattice pattern is formed. A second harmonic generation element using the polarization inversion lattice crystal of No. 8.
μｍ以上１０μｍ以下であり、分域反転領域の幅が格子
パタ−ン幅とほぼ等しいことを特徴とする請求項９の分
極反転格子結晶を用いた第２高調波発生素子。10. The width in the periodic direction of the lattice pattern is 1
10. The second harmonic generating element using the polarization inverting lattice crystal according to claim 9, wherein the domain inversion region has a width of .mu.m or more and 10 .mu.m or less and the width of the domain inversion region is substantially equal to the lattice pattern width.
トン交換層を形成し熱処理を行うことを特徴とする請求
項９ないし１０の分極反転格子結晶を用いた第２高調波
発生素子。11. The second harmonic generation device using a polarization inversion lattice crystal according to claim 9, wherein a proton exchange layer having a lattice pattern shape is formed on the crystal surface and heat treatment is performed.
の形成後、熱処理温度が２００℃以上でありかつ熱処理
時間が１０分以内であることを特徴とする請求項９の分
極反転格子結晶を用いた第２高調波発生素子。12. The polarization inversion lattice crystal according to claim 9, wherein the heat treatment temperature is 200 ° C. or higher and the heat treatment time is within 10 minutes after the formation of the lattice-patterned proton exchange layer. Second harmonic generator used.
に形成し、深さが結晶の厚さより小さく位相整合する部
分以外には分極反転格子がないことを特徴とする請求項
１ないし１２の分極反転格子結晶を用いた第２高調波発
生素子。13. The polarization inversion lattice according to claim 1, wherein the polarization inversion lattice is formed inside the crystal surface, and there is no polarization inversion lattice except in a portion having a depth smaller than the crystal thickness and phase matching. A second harmonic generation element using an inverted lattice crystal.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7848392A JPH05241217A (en) | 1992-02-28 | 1992-02-28 | Second harmonic wave generating element |
| US08/008,310 US5412502A (en) | 1992-01-24 | 1993-01-25 | Second harmonic generating element and the production method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7848392A JPH05241217A (en) | 1992-02-28 | 1992-02-28 | Second harmonic wave generating element |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05241217A true JPH05241217A (en) | 1993-09-21 |
Family
ID=13663242
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7848392A Pending JPH05241217A (en) | 1992-01-24 | 1992-02-28 | Second harmonic wave generating element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05241217A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1997015863A1 (en) * | 1995-10-26 | 1997-05-01 | Mitsubishi Cable Industries, Ltd. | Optical device |
-
1992
- 1992-02-28 JP JP7848392A patent/JPH05241217A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1997015863A1 (en) * | 1995-10-26 | 1997-05-01 | Mitsubishi Cable Industries, Ltd. | Optical device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5714198A (en) | Method of controlling regions of ferroelectric polarization domains in solid state bodies | |
| JP5235994B2 (en) | Ferroelectric domain inversion method | |
| JP3052501B2 (en) | Manufacturing method of wavelength conversion element | |
| US7170671B2 (en) | High efficiency wavelength converters | |
| JP3397433B2 (en) | Polarization inversion layer forming method and optical wavelength conversion element | |
| JP3332363B2 (en) | Method of manufacturing domain-inverted region, optical wavelength conversion element using the same, and method of manufacturing the same | |
| JPH11212128A (en) | Wavelength converting element, production thereof and solid laser device using the same | |
| JPH05241217A (en) | Second harmonic wave generating element | |
| JP2910370B2 (en) | Optical wavelength conversion element and short wavelength laser light source using the same | |
| JPH05241216A (en) | Second harmonic wave generating element | |
| JPH05241215A (en) | Second harmonic wave generating element | |
| JP2718259B2 (en) | Short wavelength laser light source | |
| JP3316987B2 (en) | Method of forming domain-inverted grating and optical waveguide | |
| JP2973642B2 (en) | Manufacturing method of optical wavelength conversion element | |
| JP2962024B2 (en) | Method for manufacturing optical waveguide and method for manufacturing optical wavelength conversion element | |
| JP2921209B2 (en) | Manufacturing method of wavelength conversion element | |
| JPH06265951A (en) | Optical wavelength converter | |
| JPH04296731A (en) | Short-wavelength laser beam source | |
| JP3398144B2 (en) | Method for manufacturing domain-inverted region | |
| JP3052654B2 (en) | Optical wavelength conversion element | |
| JPH0756201A (en) | Formation of polarization inversion grating and optical waveguide | |
| JPH0756203A (en) | Formation of polarization inversion grating and optical waveguide | |
| JPH043128A (en) | Formation of partial polarization inversion region | |
| JP3006217B2 (en) | Optical wavelength conversion element and method of manufacturing the same | |
| JPH04340525A (en) | Wavelength conversion element |