JP2605385B2 - Optical wavelength resolution measurement device - Google Patents
Optical wavelength resolution measurement deviceInfo
- Publication number
- JP2605385B2 JP2605385B2 JP63311167A JP31116788A JP2605385B2 JP 2605385 B2 JP2605385 B2 JP 2605385B2 JP 63311167 A JP63311167 A JP 63311167A JP 31116788 A JP31116788 A JP 31116788A JP 2605385 B2 JP2605385 B2 JP 2605385B2
- Authority
- JP
- Japan
- Prior art keywords
- polarization
- light
- diffraction grating
- optical wavelength
- control means
- 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 - Fee Related
Links
Landscapes
- Spectrometry And Color Measurement (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、半導体レーザ等の発光スペクトル測定およ
び分光測定を行なう測定装置に関するものである。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring apparatus for performing emission spectrum measurement and spectroscopic measurement of a semiconductor laser or the like.
従来の光波長分解測定装置においては、入力光を回折
格子を用いて波長分解し、この光を光検出器で測定して
光波長分解測定を行なうことが一般に行なわれている。
この様な光波長分解測定装置においては、回折格子の回
折効率が波長依存性および偏光依存性（回折格子に対し
てのTE光、TM光で回折効率が異なる）があるため出力光
レベルが変化してしまう（M.G.Moharam et al.“Rigoro
us coupled−wave analysis of metallic surface−rel
ief gretings" Journal of Optical society of Americ
a,vol.3,No.11,pp1780−1787,1986）回折効率の波長依
存性に関しては測定波長が分っていれば簡単に校正でき
る。しかし、偏光依存性に関しては入力光の偏光状態が
不明な場合が多い。特に入力光がシングルモード光ファ
イバを通過してきた場合はその偏光状態は測定しない限
り不明と言える。このため入力光の偏光状態に対しての
校正をするために回折格子の出力光を偏光ビームスプリ
ッタで偏光分離し、これらを個別の光検出器で検出した
後に補正演算を行なう形の偏光依存性のない光波長分解
測定装置が製作されている（例えば、アンリツ製 光ス
ペクトラムアナライザ MS9001B1）。2. Description of the Related Art In a conventional optical wavelength resolution measuring apparatus, generally, input light is wavelength-resolved using a diffraction grating, and this light is measured with a photodetector to perform optical wavelength resolution measurement.
In such an optical wavelength-resolved measuring apparatus, the output light level changes because the diffraction efficiency of the diffraction grating has wavelength dependence and polarization dependence (the diffraction efficiency differs between TE light and TM light with respect to the diffraction grating). (MGMoharam et al. “Rigoro
us coupled-wave analysis of metallic surface-rel
ief gretings "Journal of Optical society of Americ
a, vol. 3, No. 11, pp. 1780-1787, 1986) The wavelength dependence of diffraction efficiency can be easily calibrated if the measurement wavelength is known. However, regarding the polarization dependency, the polarization state of the input light is often unknown. In particular, when the input light has passed through a single mode optical fiber, its polarization state is unknown unless measured. For this reason, in order to calibrate the polarization state of the input light, the output light of the diffraction grating is polarized and separated by a polarization beam splitter, and these are detected by individual photodetectors, and then the polarization dependence is corrected. An optical wavelength-resolved measurement device without a laser has been manufactured (for example, an optical spectrum analyzer MS9001B1 manufactured by Anritsu).
上述した光波長分解測定装置においては、回折格子に
よって波長分解された後に偏光分離するため光検出器が
複数必要となり装置が大きくなる欠点があった。The above-described optical wavelength resolution measuring apparatus has a drawback that a plurality of photodetectors are required because the light is wavelength-resolved by a diffraction grating and then polarized light is separated, so that the apparatus becomes large.
本発明の目的は、上記の様な欠点を除去し、光検出器
１つでコンパクトな構成で入力光の偏光に依存しない光
波長分解測定装置を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to provide an optical wavelength resolution measuring apparatus which eliminates the above-mentioned disadvantages and has a compact configuration with one photodetector and does not depend on the polarization of input light.
本発明の光波長分解測定装置は、入力光を空間的に直
交する２偏光状態に分離する偏光分離素子と、前記２偏
光状態に分離された一方の光をもう一方の偏光状態と一
致させる偏光制御手段と、前記偏光制御手段の出力光と
偏光制御手段を通過していない一方の光とを同時に波長
分解を行なう回折格子と、前記回折格子の回折光パワー
を検波する検出器を備えた構成となっており、回折格子
への入力偏光を一定とすることで回折格子の回折効率を
補正できることを特徴とする光波長分解測定装置であ
る。The optical wavelength separation measuring apparatus according to the present invention includes a polarization separation element that separates input light into two polarization states that are orthogonal to each other spatially, and a polarization light that separates one light separated into the two polarization states into another polarization state. Control means, a diffraction grating for simultaneously wavelength-decomposing the output light of the polarization control means and one light not passing through the polarization control means, and a detector for detecting the diffracted light power of the diffraction grating The optical wavelength resolution measuring device is characterized in that the diffraction efficiency of the diffraction grating can be corrected by keeping the input polarization to the diffraction grating constant.
本発明の光波長分解測定装置では、まず入力光を偏光
ビームスプリッタで直交２偏光状態に分離する。この２
偏光状態に分離された光の一方を偏光制御手段である偏
光制御器で偏光変換して分離されたもう一方の偏光状態
の光に変換する。このことによりこれら２つの偏光分離
された光は同一偏光状態となる。この後これら２つの光
を同時に回折格子で波長分解する。このような測定にお
いては回折格子への入力光の偏光状態が一定となってい
るため光波長分解測定装置への入力光の偏光が任意であ
っても回折格子の入力偏光依存性が出力レベルに生じな
い測定ができる。In the optical wavelength resolution measuring apparatus according to the present invention, first, input light is split into two orthogonal polarization states by a polarization beam splitter. This 2
One of the lights separated into the polarization state is subjected to polarization conversion by a polarization controller, which is a polarization control means, to be converted into the other separated light having the polarization state. As a result, these two polarized light beams are in the same polarization state. Thereafter, these two lights are simultaneously wavelength-resolved by a diffraction grating. In such a measurement, the polarization state of the input light to the diffraction grating is constant, so even if the polarization of the input light to the optical wavelength resolution measurement device is arbitrary, the input polarization dependence of the diffraction grating will be at the output level. Measurements that do not occur can be made.
第１図は本発明の一実施例の構成図を示す。本実施例
では入力光200は偏光ビームスプリッタ100で２直交直線
偏光成分に分離される。その後それぞれの偏光成分が偏
光保持ファイバ101、102に結合される。一方の偏光保持
ファイバ102は偏光制御手段400として、偏光保持ファイ
バ101と同一の直線偏光を出力するように空間的に90度
捩られる。この偏光保持ファイバ101、102を回折格子に
対してTE偏光となる方向に並べて設置し、光ファイバか
らの出力光を回折格子に対してTE偏光になるようにす
る。この場合、回折格子の回折効率ηは、ηTEとなりこ
の値で校正する事で入力光パワーを回折格子の偏光依存
性の影響を受ける事無く測定できる。またこの際、直交
する偏光成分で長手方向での経路差が存在するので、回
折格子の出力光300がスリット103の長手方向に干渉縞を
生じるが、出力光300を直線的に広がったスリット103で
切りわけ、この出力光300のパワーをすべて光検出器４
を用いて受光するとにより、偏光依存性およびこの干渉
縞の影響も受けずに波長分解測定ができる。FIG. 1 shows a configuration diagram of an embodiment of the present invention. In this embodiment, the input light 200 is split by the polarization beam splitter 100 into two orthogonal linearly polarized light components. Thereafter, the respective polarization components are coupled to the polarization maintaining fibers 101 and 102. One polarization maintaining fiber 102 is spatially twisted by 90 degrees as polarization control means 400 so as to output the same linearly polarized light as the polarization maintaining fiber 101. The polarization maintaining fibers 101 and 102 are arranged side by side in the direction of the TE polarization with respect to the diffraction grating, so that the output light from the optical fiber becomes the TE polarization with respect to the diffraction grating. In this case, the diffraction efficiency η of the diffraction grating becomes η TE, and by calibrating with this value, the input light power can be measured without being affected by the polarization dependence of the diffraction grating. Also, at this time, since there is a path difference in the longitudinal direction between the orthogonal polarization components, the output light 300 of the diffraction grating causes interference fringes in the longitudinal direction of the slit 103, but the slit 103 in which the output light 300 spreads linearly. And all of the power of this output light 300
, Wavelength-resolved measurement can be performed without being affected by the polarization dependence and the interference fringes.
本実施例には様々な変形例がある。一方の偏光をもう
一方の偏光に変換する偏光制御手段としてファラデーロ
テータを用いることもLiNbO3の結晶を用いた偏光制御素
子を用いる事もできる。また回折格子への入射偏光状態
はどの様な偏光状態でも良く、TE偏光に限らず、TM偏光
あるいは他の直線偏光でも良いし、円偏光でも良い。た
だしこの際にはその偏光状態に対する回折効率によって
出力パワーを校正する必要がある。また偏光状態を一致
させた光を合波する方法も光ファイバ端を空間的に並べ
るだけでなく、各光ファイバから出射した光をハーフミ
ラー等の合波器で混合し、その光を回折格子に入力する
こともできる。この際にはスリット上に干渉縞は生じな
い。There are various modifications in this embodiment. A Faraday rotator can be used as polarization control means for converting one polarized light into another polarized light, or a polarization control element using a LiNbO 3 crystal can be used. The polarization state incident on the diffraction grating may be any polarization state, and is not limited to TE polarization, but may be TM polarization or another linear polarization, or circular polarization. However, in this case, it is necessary to calibrate the output power based on the diffraction efficiency for the polarization state. In addition, the method of multiplexing light having the same polarization state is not only spatially arranging the ends of the optical fibers, but also mixing the light emitted from each optical fiber with a multiplexer such as a half mirror, and converting the light to a diffraction grating. Can also be entered. In this case, no interference fringes are generated on the slit.
以上説明した様に本発明によれば、入力光の偏光状態
を一定として測定することで、回折格子の回折効率の偏
波依存性を簡単に補償することができ、光波長分解した
後に光検出器一個のみの簡単な構成で、容易に回折格子
の回折効率の偏光依存性を校正できる。As described above, according to the present invention, it is possible to easily compensate for the polarization dependence of the diffraction efficiency of the diffraction grating by measuring the polarization state of the input light at a constant level, and to perform light detection after light wavelength decomposition. The polarization dependence of the diffraction efficiency of the diffraction grating can be easily calibrated with a simple configuration using only one device.
第１図は、本発明の典型的な実施例である光波長分解測
定装置の図である。 図中、 ２……回折格子、103……スリット、４……光検出器、1
00……偏光ビームスプリッタ、101、102……偏光保持フ
ァイバ、200……入力光、300……出力光、400……偏光
制御手段 である。FIG. 1 is a diagram of an optical wavelength resolution measuring apparatus which is a typical embodiment of the present invention. In the figure, 2 ... Diffraction grating, 103 ... Slit, 4 ... Photodetector, 1
00: polarization beam splitter; 101, 102: polarization maintaining fiber; 200: input light; 300: output light; 400: polarization control means.
Claims (1)
離する偏光分離素子と、前記２偏光状態に分離された一
方の光をもう一方の偏光状態と一致させる偏光制御手段
と、前記偏光制御手段の出力光と偏光制御手段を通過し
ていない一方の光とを同時に波長分解を行なう回折格子
と、前記回折格子の回折光パワーを検波する検出器とを
備え、前記回折格子に入力する光の偏光状態を一定の偏
光状態に揃えたことを特徴とする光波長分解測定装置。A polarization splitting element for separating input light into two spatially orthogonal polarization states; a polarization control means for matching one of the two polarized light states with another polarization state; A diffraction grating for simultaneously wavelength-decomposing the output light of the polarization control means and one of the lights not passing through the polarization control means, and a detector for detecting the diffracted light power of the diffraction grating. An optical wavelength resolution measuring device, wherein the polarization state of light to be emitted is set to a constant polarization state.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63311167A JP2605385B2 (en) | 1988-12-08 | 1988-12-08 | Optical wavelength resolution measurement device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63311167A JP2605385B2 (en) | 1988-12-08 | 1988-12-08 | Optical wavelength resolution measurement device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02156124A JPH02156124A (en) | 1990-06-15 |
| JP2605385B2 true JP2605385B2 (en) | 1997-04-30 |
Family
ID=18013897
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63311167A Expired - Fee Related JP2605385B2 (en) | 1988-12-08 | 1988-12-08 | Optical wavelength resolution measurement device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2605385B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1529204A1 (en) * | 2002-07-12 | 2005-05-11 | River Diagnostics B.V. | Optical spectrometer |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6507685B1 (en) * | 2001-09-20 | 2003-01-14 | Capella Photonics, Inc. | Method and apparatus for servo-based spectral array alignment in optical systems |
| JP4645173B2 (en) * | 2004-11-26 | 2011-03-09 | 株式会社ニコン | Spectroscope and microspectroscopic device provided with the same |
| JP2006242876A (en) * | 2005-03-07 | 2006-09-14 | Namiki Precision Jewel Co Ltd | Wavelength monitor unit |
| JP2007240228A (en) * | 2006-03-07 | 2007-09-20 | Fujifilm Corp | Optical tomographic imaging apparatus |
| JP5634291B2 (en) * | 2011-02-10 | 2014-12-03 | アンリツ株式会社 | Optical spectrum measuring apparatus and optical spectrum measuring method |
| JP5861873B2 (en) * | 2012-01-26 | 2016-02-16 | 株式会社ニコン | Spectrometer and microspectroscopic system |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63284431A (en) * | 1987-05-15 | 1988-11-21 | Iwatsu Electric Co Ltd | Spectro-photometer |
| JPS63284432A (en) * | 1987-05-15 | 1988-11-21 | Iwatsu Electric Co Ltd | Spectrophotometer |
-
1988
- 1988-12-08 JP JP63311167A patent/JP2605385B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63284431A (en) * | 1987-05-15 | 1988-11-21 | Iwatsu Electric Co Ltd | Spectro-photometer |
| JPS63284432A (en) * | 1987-05-15 | 1988-11-21 | Iwatsu Electric Co Ltd | Spectrophotometer |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1529204A1 (en) * | 2002-07-12 | 2005-05-11 | River Diagnostics B.V. | Optical spectrometer |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02156124A (en) | 1990-06-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |