JPH0576615B2 - - Google Patents
Info
- Publication number
- JPH0576615B2 JPH0576615B2 JP14469684A JP14469684A JPH0576615B2 JP H0576615 B2 JPH0576615 B2 JP H0576615B2 JP 14469684 A JP14469684 A JP 14469684A JP 14469684 A JP14469684 A JP 14469684A JP H0576615 B2 JPH0576615 B2 JP H0576615B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- optical waveguide
- planar optical
- polarized light
- acoustic wave
- 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.)
- Expired - Lifetime
Links
- 230000003287 optical effect Effects 0.000 claims description 51
- 238000010897 surface acoustic wave method Methods 0.000 claims description 19
- 230000001902 propagating effect Effects 0.000 claims description 5
- 239000010936 titanium Substances 0.000 description 6
- 230000031700 light absorption Effects 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- 229910013641 LiNbO 3 Inorganic materials 0.000 description 3
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 3
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229910052719 titanium Inorganic materials 0.000 description 3
- 230000002596 correlated effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000006096 absorbing agent Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000009396 hybridization Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Landscapes
- Optical Integrated Circuits (AREA)
Description
【発明の詳細な説明】
〔技術分野〕
本発明は平面光回路に関し、特に不要光ビーム
を導く光導波路を持つ平面光回路に関するもので
ある。DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a planar optical circuit, and particularly to a planar optical circuit having an optical waveguide for guiding an unnecessary light beam.
一般に平面光導波路は、光・音響（AO）スペ
クトラムアナライザ、AOコリレータ等のハイブ
リツド化、モノリシツク化のために用いられる。
弾性表面波による光の回折を利用したAOコリレ
ータは２信号の相関を瞬時にうるものであり、次
のように構成されている。すなわち平面光回路
は、誘電体表面に形成された平面光導波路の端面
より入射した拡がり角を有する光を平面レンズに
よりコリメート光に変換し、弾性表面波により偏
向されたコリメート光が相関信号として検出され
る。このとき、弾性表面波により回折されないコ
リメート光（今後、０次光と呼ぶ）も平面光導波
路を伝搬している。
Generally, planar optical waveguides are used for hybridization and monolithization of optical/acoustic (AO) spectrum analyzers, AO correlators, etc.
The AO correlator, which uses light diffraction by surface acoustic waves, can instantly correlate two signals and is configured as follows. In other words, a planar optical circuit converts light with a divergence angle incident from the end face of a planar optical waveguide formed on a dielectric surface into collimated light using a plane lens, and detects the collimated light deflected by a surface acoustic wave as a correlated signal. be done. At this time, collimated light (hereinafter referred to as zero-order light) that is not diffracted by the surface acoustic wave is also propagating through the planar optical waveguide.
従つて、相関信号のみを検出するには、偏向光
と０次光を分離する必要がある。 Therefore, in order to detect only the correlation signal, it is necessary to separate the polarized light and the zero-order light.
偏向光と０次光は、光の波長、弾性表面波の励
振周波数、及び、伝搬速度と平面光薄膜導波路の
屈折率で決まるプラグ角をなして伝搬するため、
光の伝搬距離をかなり長くすれば、すなわち、平
面光導波路を長くすれば、平面導波路内で０次光
と１次光を分離でき、平面導波路の端面において
相関信号のみを検出できる。 Since the polarized light and the zero-order light propagate at a plug angle determined by the wavelength of the light, the excitation frequency of the surface acoustic wave, the propagation speed, and the refractive index of the planar optical thin film waveguide,
If the propagation distance of light is made considerably long, that is, if the planar optical waveguide is made long, it is possible to separate the zero-order light and the first-order light within the planar waveguide, and detect only the correlated signal at the end face of the planar waveguide.
しかし、このときは、AOコリレータに用いる
基板の大型化につながり、基板入手の困難さ及び
高価格化が生じる。 However, in this case, the substrate used for the AO correlator becomes larger, making it difficult to obtain the substrate and increasing the price.
このような大型化、及び、高価格化を防ぐ方法
としては第１図に示すように、平面レンズを３個
用い、かつ空間フイルタを用いる方法が提案され
ている。 As a method for preventing such an increase in size and price, a method has been proposed that uses three plane lenses and a spatial filter, as shown in FIG.
すなわち、この平面光回路は誘電体表面に設け
た平面光導波路１１の端面より光源１２から放射
された拡がり角を有する光を平面光導波路１１に
導波し、拡がり角を有しながら伝搬する光１９を
平面コリメートレンズ１３によりコリメート光
（今後入射光と呼ぶ）２０に変換する。この入射
光２０は入力信号S1(t)により強度変調され、弾性
表面波発生用電極１７より発生する弾性表面波２
２が、入力信号S2(t)により振巾変調されていると
き、弾性表面波２２により回折される。この回折
された偏向光２１は、S1(t)とS2(t)の積の信号とな
る。このとき、偏向光２１の強度は、入射光２０
と弾性表面波２２との回折効率で決まるため、回
折されない非偏向光２３が残る。この偏向光２１
と非偏向光２３とを分離するため、平面レンズ１
４を用いる。すなわち、コリメート光である偏向
光２１と非偏向２３は、平面レンズ１４を入射す
ることにより、それぞれ集光され空間的に平面光
導波路上で分離される。その位置においては導波
型空間フイルタ１６により非偏向光２３のみを遮
断し、偏向光２１を再び平面コリメートレンズ１
５に入射させる。コリメート光に変換された偏向
光は受光素子１８に入射させることにより相関信
号のみが簡単に検出される。従つて、この平面光
回路１１では３個の平面レンズ１３，１４，１５
を用いることにより、AOコリレータの小型化、
低価格化が簡単に実現できる。 That is, this planar optical circuit guides light having a divergence angle emitted from a light source 12 from the end face of a planar optical waveguide 11 provided on the surface of a dielectric material to the planar optical waveguide 11, and the light propagates while having a divergence angle. 19 is converted into collimated light (hereinafter referred to as incident light) 20 by a flat collimating lens 13. This incident light 20 is intensity-modulated by the input signal S 1 (t), and the surface acoustic wave 2 generated by the surface acoustic wave generation electrode 17 is
2 is diffracted by the surface acoustic wave 22 when it is amplitude modulated by the input signal S 2 (t). This diffracted polarized light 21 becomes a signal of the product of S 1 (t) and S 2 (t). At this time, the intensity of the polarized light 21 is equal to the intensity of the incident light 20
Since it is determined by the diffraction efficiency of the surface acoustic wave 22 and the surface acoustic wave 22, the unpolarized light 23 that is not diffracted remains. This polarized light 21
A plane lens 1 is used to separate the unpolarized light 23 from the
4 is used. That is, the polarized light 21 and the unpolarized light 23, which are collimated lights, enter the plane lens 14, are respectively focused, and are spatially separated on the plane optical waveguide. At that position, the waveguide spatial filter 16 blocks only the unpolarized light 23, and the polarized light 21 is returned to the plane collimating lens 1.
5. By making the polarized light converted into collimated light enter the light receiving element 18, only the correlation signal is easily detected. Therefore, this planar optical circuit 11 includes three planar lenses 13, 14, 15.
By using
Lower prices can be easily achieved.
なお光源１２は半導体レーザからなり、平面光
導波路１１は例えば、ニオブ酸リチウム
（LiNbO3）基板の表面全面にチタン（Ti）を拡
散し設けた光導波路等からなり、また、平面レン
ズ１３，１４，１５は、フレネルレンズ，ジオデ
シツクレンズ等からなる。しかしながら、導波型
空間フイルタについては、いまだに具体的な素
子、及び、その実現方法は提案されていない。 The light source 12 is made of a semiconductor laser, the planar optical waveguide 11 is made of, for example, an optical waveguide in which titanium (Ti) is diffused over the entire surface of a lithium niobate (LiNbO 3 ) substrate, and the planar optical waveguide 11 is made of a lithium niobate (LiNbO 3 ) substrate with titanium (Ti) diffused over the entire surface. , 15 are Fresnel lenses, geodesic lenses, etc. However, as for the waveguide type spatial filter, no specific element or method for realizing the same has been proposed yet.
したがつて、従来の平面光回路はこの導波型空
間フイルタ１６による欠点を有し、いまだ十分な
ものとは云えなかつた。 Therefore, the conventional planar optical circuit has drawbacks due to the waveguide type spatial filter 16, and has not been said to be sufficient.
本発明の目的は、従来の平面光回路における欠
点を除去し、従来の導波型空間フイルタに代わる
役割を果たす平面光回路を提供するものである。
SUMMARY OF THE INVENTION An object of the present invention is to provide a planar optical circuit that eliminates the drawbacks of conventional planar optical circuits and serves as a substitute for conventional waveguide spatial filters.
本発明によれば、誘電体表面に形成された平面
光導波路と、該平面光導波路を伝搬する光を回折
せしめる弾性表面波発生用電極と、前記、平面光
導波路を伝搬する光ビームのうち、偏向光と非偏
光を分離する平面レンズと、前記非偏向光である
不要光ビームを所定の場所に導くための三次元光
導波路とを含むことを特徴とする平面光回路が得
られる。
According to the present invention, a planar optical waveguide formed on a dielectric surface, a surface acoustic wave generating electrode that diffracts light propagating through the planar optical waveguide, and a light beam propagating through the planar optical waveguide, A planar optical circuit is obtained that includes a planar lens that separates polarized light and non-polarized light, and a three-dimensional optical waveguide that guides the unnecessary light beam that is the non-polarized light to a predetermined location.
次に本発明の実施例について図面を参照して詳
細に説明する。
Next, embodiments of the present invention will be described in detail with reference to the drawings.
第２図は本発明の一実施例を示す。第２図にお
いて、本発明の一実施例は時間積分型光・音響
（AO）コリメータで、誘電体表面に形成された
平面光導波路４２と、該平面光導波路４２の端面
に設けられた光源３１と、光源３１から放射され
た光を集光する平面コリメートレンズ３２と、平
面コリメートレンズ３２により変換されたコリメ
ート光を回折する弾性表面波４１を発生する弾性
表面波発生電極４０と、回折された偏向光３８と
回折されない非偏向光３９を分離する平面レンズ
３３と、非偏向光３９を非偏向光吸収端面領域に
導く三次元（矩形）光導波路４３と、偏向光を焦
光せしめる平面コリメートレンズ３４と、該平面
コリメートレンズ３４により焦光した偏向光４７
を受光する受光素子３５とを含む。 FIG. 2 shows an embodiment of the invention. In FIG. 2, one embodiment of the present invention is a time-integrating optical/acoustic (AO) collimator, which includes a planar optical waveguide 42 formed on a dielectric surface and a light source 31 provided on the end face of the planar optical waveguide 42. , a plane collimating lens 32 that collects the light emitted from the light source 31, a surface acoustic wave generating electrode 40 that generates a surface acoustic wave 41 that diffracts the collimated light converted by the plane collimating lens 32, and a surface acoustic wave generating electrode 40 that generates a surface acoustic wave 41 that diffracts the collimated light converted by the plane collimating lens 32. A plane lens 33 that separates polarized light 38 and non-polarized light 39 that is not diffracted, a three-dimensional (rectangular) optical waveguide 43 that guides the non-polarized light 39 to the non-polarized light absorption end face region, and a plane collimating lens that focuses the polarized light. 34, and polarized light 47 focused by the plane collimating lens 34.
and a light receiving element 35 that receives the light.
本実施例において、光源３１より放射された拡
がり角を有する光３６は、平面コリメートレンズ
３２によりコリメート光（今後、入射光と呼ぶ）
３７に変換される。この入射光３７は、弾性表面
波発生電極４０より発生する弾性表面波４１によ
り回折され、偏向光３８を生じるとともに、回折
されない非偏向光３９も残る。偏向光３８と非偏
向光３９は平面光導波路４２内で空間的に分離す
るため、凸レンズ作用を有する平面レンズ３３に
より、それぞれ集光される。 In this embodiment, light 36 having a divergence angle emitted from a light source 31 is collimated by a plane collimating lens 32 (hereinafter referred to as incident light).
37. This incident light 37 is diffracted by the surface acoustic wave 41 generated by the surface acoustic wave generating electrode 40 to generate polarized light 38 and also leaves unpolarized light 39 that is not diffracted. Since the polarized light 38 and the unpolarized light 39 are spatially separated within the planar optical waveguide 42, they are each focused by the planar lens 33 having a convex lens function.
このとき、AOコリレータにとつては不要光で
ある非偏向光３９を導く不要光用三次元光導波路
４３は非偏向光の焦点位置に設けられ非偏向光４
６を入射させている。 At this time, the unnecessary light three-dimensional optical waveguide 43 that guides the unpolarized light 39, which is unnecessary light for the AO correlator, is provided at the focal position of the unpolarized light.
6 is input.
したがつて、非偏向光４６は、偏向光３８用の
平面レリメートレンズ３４に入射されずにかつ、
偏向光の受光素子３５に入射しないように非偏向
光吸収端面領域４５に導びかれる。非偏向光吸収
端面領域４５に図示するように光吸収体を設けて
おけば、非偏向光４６はここで吸収される。又、
何もなければ光はここから外部へ送出される。こ
の結果、不要光である非偏向光を簡単に除去でき
る。 Therefore, the unpolarized light 46 is not incident on the plane relimator lens 34 for the polarized light 38, and
The polarized light is guided to the non-polarized light absorption end face region 45 so as not to enter the light receiving element 35 of the polarized light. If a light absorber is provided in the non-polarized light absorption end face region 45 as shown in the figure, the non-polarized light 46 will be absorbed there. or,
If there is nothing else, light will be sent out from here. As a result, unnecessary non-polarized light can be easily removed.
従つて偏向光４７は平面コリメートレンズ３４
に入射し、コリメート光に変換され、受光素子３
５で検出される。 Therefore, the polarized light 47 is transmitted through the plane collimating lens 34.
is incident on the light receiving element 3 and is converted into collimated light.
Detected at 5.
なお、不要光用矩三次元導波路４３の深さは、
平面光導波路４２と同じにし、その幅は、平面レ
ンズ３３で集光された焦点での非偏向光４６のビ
ームスポツトサイズとほぼ同じにする。この結
果、非偏向光４６は、ほぼ100％不要光用三次元
光導波路４３に入射され、反射、及び、散乱によ
る偏向光３８への影響はない。また、不要光用三
次元光導波路４３のまわりは、平面光導波路４２
と不要光用三次元光導波路４３が有する屈折率よ
り低い屈折率を有する低屈折率領域４４からな
る。 In addition, the depth of the rectangular three-dimensional waveguide 43 for unnecessary light is
It is made the same as the planar optical waveguide 42, and its width is made approximately the same as the beam spot size of the unpolarized light 46 at the focal point condensed by the planar lens 33. As a result, almost 100% of the unpolarized light 46 enters the three-dimensional optical waveguide 43 for unnecessary light, and there is no influence on the polarized light 38 due to reflection or scattering. Furthermore, around the three-dimensional optical waveguide 43 for unnecessary light, there is a planar optical waveguide 42.
and a low refractive index region 44 having a refractive index lower than that of the three-dimensional optical waveguide 43 for unnecessary light.
たとえば、誘電体をニオブ酸リチウム
（LiNbO3）とすれば、平面光導波路４２の領域
と不要光用三次元光導波路４３の領域のみにチタ
ン（Ti）を拡散すればよい。 For example, if lithium niobate (LiNbO 3 ) is used as the dielectric, titanium (Ti) may be diffused only in the area of the planar optical waveguide 42 and the area of the three-dimensional optical waveguide 43 for unnecessary light.
本発明の一実施例では、平面光回路をAOコリ
レータにおいて不要光ビームである非偏向光と偏
向光を分離するために用いているが、平面光回路
の働きは、この実施例に限定されるものではな
く、不要光ビーム専用に三次元（矩形）光導波路
を形成しているものならどのようなものでもよ
い。 In one embodiment of the present invention, a planar optical circuit is used in an AO correlator to separate unpolarized light and polarized light, which are unnecessary light beams, but the function of the planar optical circuit is limited to this embodiment. Any type of optical waveguide may be used as long as it forms a three-dimensional (rectangular) optical waveguide exclusively for unnecessary light beams.
本発明は、以上説明したように非偏向光を容易
に導びくことができ、かつ小形化を可能にする効
果がある。
As explained above, the present invention has the effect of easily guiding unpolarized light and making it possible to downsize.
第１図は、従来の平面光回路を示す図、第２図
は、本発明の一実施例を示す平面図である。
１１，４２……平面光導波路、４３……不要光
用矩形光導波路、１２，３１……光源、１３，１
５，３２，３４……平面コリメートレンズ、１
４，３３……平面レンズ、１９，３６……拡がり
角を有する光、２０，３７……偏向光、２３，３
９，４６……非偏向光、１６……導波型空間フイ
ルタ、１８，３５……受光素子、１７，４０……
弾性表面波発生用電極、２２，４１……弾性表面
波、４３……不要光用三次元（矩形）光導波路、
４４……低屈折率領域、４５……非偏向光吸収端
面領域。
FIG. 1 is a diagram showing a conventional planar optical circuit, and FIG. 2 is a plan view showing an embodiment of the present invention. 11, 42... Planar optical waveguide, 43... Rectangular optical waveguide for unnecessary light, 12, 31... Light source, 13, 1
5, 32, 34...Plane collimating lens, 1
4,33...Plane lens, 19,36...Light with a divergence angle, 20,37...Polarized light, 23,3
9,46...unpolarized light, 16...waveguide spatial filter, 18,35...light receiving element, 17,40...
Surface acoustic wave generation electrode, 22, 41... surface acoustic wave, 43... three-dimensional (rectangular) optical waveguide for unnecessary light,
44...Low refractive index region, 45...Non-polarized light absorption end face region.
Claims (1)
平面光導波路を伝搬する光を回折せしめる弾性表
面波発生用電極と、前記平面光導波路を伝搬する
光ビームのうち、偏向光と非偏向光を分離する平
面レンズと、前記非偏向光である不要光ビームを
所定の場所に導くための三次元光導波路とを含む
ことを特徴とする平面光回路。1 A planar optical waveguide formed on a dielectric surface, a surface acoustic wave generation electrode that diffracts light propagating through the planar optical waveguide, and polarized light and non-polarized light among the light beams propagating through the planar optical waveguide. and a three-dimensional optical waveguide for guiding the unnecessary light beam, which is the non-polarized light, to a predetermined location.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14469684A JPS6123119A (en) | 1984-07-12 | 1984-07-12 | Plane optical circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14469684A JPS6123119A (en) | 1984-07-12 | 1984-07-12 | Plane optical circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6123119A JPS6123119A (en) | 1986-01-31 |
| JPH0576615B2 true JPH0576615B2 (en) | 1993-10-25 |
Family
ID=15368141
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14469684A Granted JPS6123119A (en) | 1984-07-12 | 1984-07-12 | Plane optical circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6123119A (en) |
-
1984
- 1984-07-12 JP JP14469684A patent/JPS6123119A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6123119A (en) | 1986-01-31 |
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