JPH0244219A - Wavelength detector - Google Patents
Wavelength detectorInfo
- Publication number
- JPH0244219A JPH0244219A JP19496788A JP19496788A JPH0244219A JP H0244219 A JPH0244219 A JP H0244219A JP 19496788 A JP19496788 A JP 19496788A JP 19496788 A JP19496788 A JP 19496788A JP H0244219 A JPH0244219 A JP H0244219A
- Authority
- JP
- Japan
- Prior art keywords
- diameter
- image sensor
- interference fringe
- wavelength
- linear image
- 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
- BJQHLKABXJIVAM-UHFFFAOYSA-N bis(2-ethylhexyl) phthalate Chemical compound CCCCC(CC)COC(=O)C1=CC=CC=C1C(=O)OCC(CC)CCCC BJQHLKABXJIVAM-UHFFFAOYSA-N 0.000 claims abstract description 14
- 238000001514 detection method Methods 0.000 claims abstract description 13
- 230000003287 optical effect Effects 0.000 claims abstract description 6
- 238000003384 imaging method Methods 0.000 claims abstract description 5
- 230000010355 oscillation Effects 0.000 description 12
- 238000010586 diagram Methods 0.000 description 11
- 238000000034 method Methods 0.000 description 5
- 239000012634 fragment Substances 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000006748 scratching Methods 0.000 description 1
- 230000002393 scratching effect Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J9/00—Measuring optical phase difference; Determining degree of coherence; Measuring optical wavelength
- G01J9/02—Measuring optical phase difference; Determining degree of coherence; Measuring optical wavelength by interferometric methods
- G01J9/0246—Measuring optical wavelength
Landscapes
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- General Physics & Mathematics (AREA)
- Lasers (AREA)
- Spectrometry And Color Measurement (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は単色光の中心波長検出装置に関するものである
。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a center wavelength detection device for monochromatic light.
従来の技術
近年、半導体プロセス？はじめとする微細加工に、短波
長域での高出力、高効率のレーザであるエキシマレーザ
を利用することが注目されている。Conventional technology In recent years, semiconductor process? The use of excimer lasers, which are high-power, high-efficiency lasers in the short wavelength range, is attracting attention for microfabrication.
エキシマレーザの発振線は０．６ｎｍ程度と広いため、
光学系の色収差補正が必要である。ところが紫外域であ
るため色消しレンズの製作が困難であり、一般に光共撮
器中に狭帯域化素子？設け、発振線幅ｉｏ、ＯＯｅｓｎ
ｍ程度にまで単色化している。The oscillation line of excimer laser is wide, about 0.6 nm, so
It is necessary to correct chromatic aberration in the optical system. However, since it is in the ultraviolet region, it is difficult to manufacture an achromatic lens, and a narrow band narrowing element is generally used in the optical camera. setting, oscillation linewidth io, OOesn
It has become monochromatic to about m.
このように発振線幅を単色化した場合、波長選択素子の
調整によりその中心波長全利得バンド幅内の任意の値に
設定可能である。発振波長を任意の値に精密に設定でき
れば、化学をはじめとする種々の応用分野におけるエキ
シマレーザの有用性がますます高まる。このような、発
振波長全任意の値に精密に設定できる機構を備えたエキ
シマレーザ装置の実現には、レーザ光の中心波長を精密
に検出し制御する方法が必要になる。When the oscillation linewidth is made monochromatic in this way, it can be set to any value within the total gain bandwidth of the center wavelength by adjusting the wavelength selection element. If the oscillation wavelength can be precisely set to an arbitrary value, excimer lasers will become increasingly useful in various application fields including chemistry. In order to realize such an excimer laser device equipped with a mechanism that can precisely set the oscillation wavelength to any desired value, a method for precisely detecting and controlling the center wavelength of the laser beam is required.
レーザ光の中心波長検出方法の例としては、特願昭６２
−２４２３７８号に記載のものがある。As an example of a method for detecting the center wavelength of laser light,
There is one described in No.-242378.
第７図に示すように、レーザ光の一部をファプリペロー
エタロン１２を通過させることにより形成される干渉縞
１４の位置全イメージセンサ１３で読み敗り、この干渉
縞の位置と目標波長に関連した位置との差に比例した信
号を信号処理器１５より取り出している。As shown in FIG. 7, the position of interference fringes 14 formed by passing a part of the laser beam through the Fabry-Perot etalon 12 is completely read by the image sensor 13, and the position of the interference fringes and the target wavelength are not correct. A signal proportional to the difference with the related position is extracted from the signal processor 15.
発明が解決しようとする課題
しかし、このような従来の方式では、周囲温度の変動や
振動等によってファプリペローエタロンとイメージセン
サの相対位置関係に狂いを生じると、干渉縞の結像位置
が変化してしまうため、長期間にわたる精密な検出は困
難である。そのため、おおむね１ケ月毎に、外部の波長
基準を用いた定期的な波長の枚正という煩雑な作業が必
要不可欠であった。本発明はこのような課題を解決する
ためになされたもので、長期間にわたって単色光の中心
波長を精度良く検出できる波長検出装置を提供するもの
である。Problems to be Solved by the Invention However, with such conventional methods, if the relative positional relationship between the Fabry-Perot etalon and the image sensor becomes distorted due to fluctuations in ambient temperature or vibration, the imaging position of the interference fringes changes. Therefore, accurate detection over a long period of time is difficult. Therefore, it has been necessary to carry out the troublesome work of periodically correcting the wavelength using an external wavelength standard, approximately every month. The present invention has been made to solve these problems, and it is an object of the present invention to provide a wavelength detection device that can accurately detect the center wavelength of monochromatic light over a long period of time.
課題を解決する定めの手段
この課題を解決するために本発明は、ファプリペローエ
タロンと結像光学系と受光素子を具備した波長検出装置
において、干渉縞の掻音測定するようにしたものである
。Determined Means for Solving the Problem In order to solve this problem, the present invention is a wavelength detection device equipped with a Fabry-Perot etalon, an imaging optical system, and a light receiving element, in which the scratching of interference fringes is measured. be.
作用
この構成により、外的な要因によって、ファプリペロー
エタロンとリニアイメージセンサとの相対位置関係に狂
いが生じても、干渉縞の径の変化はその位置の変化はど
大きくはないので、単色光の干渉縞の径を長期間にわた
って精度よく測定できることとなる。With this configuration, even if the relative positional relationship between the Fapri-Perot etalon and the linear image sensor is disturbed due to external factors, the change in the diameter of the interference fringes will not be large, so the monochromatic The diameter of the interference fringes of light can be measured with high precision over a long period of time.
実施例
第１図は本発明の一実施例である波長検出装置の概略図
であり、ファプリペローエタロン１２、結像光学系であ
るレンズ１１、受光素子であるリニアイメージセンサ１
３、および信号処理器１５より構成されている。第１図
において、単色光がレンズ１１とファプリペローエタロ
ン１２を通り、リニアイメージセンサ１３上に同心円状
の干渉縞１４が形成される。リニアイメージセンサ１３
は干渉縞１４の中心を通るように配置されており、特定
の干渉縞の断片間距離すなわち直径音読み取る。外的な
要因によって、ファプリペローエタロン１２とリニアイ
メージセンサ１３との相対位置関係に狂いが生じても、
干渉縞１４の直径の変化はその位置の変化はど大きくは
ない。したがって、第１図の実施例によｎば、波長検出
装置の長期間にわ几る安定性を飛躍的に高めることがで
きる。Embodiment FIG. 1 is a schematic diagram of a wavelength detection device which is an embodiment of the present invention, and includes a Fabry-Perot etalon 12, a lens 11 which is an imaging optical system, and a linear image sensor 1 which is a light receiving element.
3 and a signal processor 15. In FIG. 1, monochromatic light passes through a lens 11 and a Fabry-Perot etalon 12, and concentric interference fringes 14 are formed on a linear image sensor 13. Linear image sensor 13
is arranged to pass through the center of the interference fringe 14, and reads the distance between fragments of a particular interference fringe, that is, the diameter. Even if the relative positional relationship between the Fapri-Perot etalon 12 and the linear image sensor 13 is distorted due to external factors,
The change in the diameter of the interference fringes 14 and the change in its position are not very large. Therefore, according to the embodiment shown in FIG. 1, the long-term stability of the wavelength detection device can be dramatically improved.
信号処理器１５には、目標波長で形成される干渉縞の直
径があらかじめ与えられてシシ、リニアイメージセンサ
１３で読み取られた直径との差に比例した信号を出力す
る。The signal processor 15 is given the diameter of the interference fringes formed at the target wavelength in advance, and outputs a signal proportional to the difference between the diameter and the diameter read by the linear image sensor 13.
第２図は本発明の異なる実施例である波長検出装置の概
略図である。第２図においては、リニアイメージセンサ
１３は干渉縞１４の中心を通るようには配置されていな
いので、信号処理器１６で演算処理を行い、干渉縞１４
の直径を算出している。第３図に示すように、リニアイ
メージセンサの受光部は一定の面積を持っているので、
ＩＪ ニアイメージセンサ１３が干渉縞１４の直径上か
らはずれていると、光強度信号は非対称となる。この対
称性からのずれ量をＸとすると、干渉縞１４の中心から
リニアイメージセンサ１３までの距離２は、Ｘに対して
単調増加する関数ｆで、ｚ＝ｆ（ｘ）
と表わせる。したがって、干渉縞１４の直径りはリニア
イメージセンサ１３に結像された干渉縞断片間の距離を
Ｌとして、
Ｄ＝−ｆフ二曹古７
と算出できることになる。第２図の実施例においては、
リニアイメージセンサ１３は必ずしも干渉縞１４の中心
を通るように配置されていなくても工（、直径読み取り
の精度はさらに向上する。FIG. 2 is a schematic diagram of a wavelength detection device according to a different embodiment of the present invention. In FIG. 2, since the linear image sensor 13 is not arranged to pass through the center of the interference fringes 14, the signal processor 16 performs arithmetic processing, and the interference fringes 14 are
Calculating the diameter of As shown in Figure 3, the light receiving part of the linear image sensor has a certain area, so
If the IJ near image sensor 13 is deviated from the diameter of the interference fringes 14, the light intensity signal becomes asymmetrical. Letting the amount of deviation from this symmetry be X, the distance 2 from the center of the interference fringes 14 to the linear image sensor 13 is a function f that monotonically increases with respect to X, and can be expressed as z=f(x). Therefore, the diameter of the interference fringe 14 can be calculated as follows, where L is the distance between the interference fringe fragments imaged on the linear image sensor 13. In the embodiment of FIG.
Even if the linear image sensor 13 is not necessarily arranged to pass through the center of the interference fringes 14, the accuracy of diameter reading can be further improved.
第４図も本発明の異なる実施例金示した概略図である。FIG. 4 is also a schematic diagram showing a different embodiment of the present invention.
第４図においては、２次元イメージセンサ４１を用いて
、同−干渉縞上にある２点の間隔の最大値音読み取るこ
とにより、干渉縞１４の直径を検出している。第４図の
実施例においては、干渉縞１４は２次元イメージセンサ
４１上のどの部分に結像さｎていても工く、第２図の実
施例と同程度の検出精度の安定性が達成できる。In FIG. 4, the diameter of the interference fringe 14 is detected by using a two-dimensional image sensor 41 to read the maximum sound value between two points on the same interference fringe. In the embodiment shown in FIG. 4, the interference fringes 14 can be imaged on any part of the two-dimensional image sensor 41, and the stability of detection accuracy comparable to that of the embodiment shown in FIG. 2 is achieved. can.
以上の実施例はいずれも、干渉縞が同心円状に結像して
いる場合の実施例である。第５図に示す、Ｃうに、ファ
プリペローエタロン１２、レンズ１１、およびイメージ
センサ１３の相対位置関係にエリ干渉縞１４が楕円形状
を示す場合がある。The above embodiments are all embodiments in which interference fringes are formed concentrically. As shown in FIG. 5, the interference fringes 14 may have an elliptical shape in the relative positional relationship of the Fabry-Perot etalon 12, the lens 11, and the image sensor 13.
その場合、第１図の実施例においては、リニアイメージ
センサ１３を干渉縞の楕円の長径上、または短径上に配
置すればよい。第４図の実施例においては、同−干渉縞
上にある２点の間隔の最大値、または最小値を読み取る
ことにより楕円の長径ま几は短径を検出できる。In that case, in the embodiment shown in FIG. 1, the linear image sensor 13 may be placed on the major axis or minor axis of the ellipse of the interference fringes. In the embodiment shown in FIG. 4, the major axis or minor axis of the ellipse can be detected by reading the maximum value or minimum value of the interval between two points on the same interference fringe.
第６図は本発明をエキシマレーザの発振波長制御に応用
した例の概略図である。第６図において、レーザ光の一
部が本発明の波長検出装置６２に導かれ、波長検出装置
６２は、レーザの発振波長と目標波長との差に比例した
信号を、エキシマレーザ装置に内蔵された発振波長を変
化させる機構６１ｂに送り、発振波長が制御される。発
振波長を変化させる機構としては、光弁振器中に設けら
レタエアスペースエタロンのギャップ間の気圧を変化さ
せる方法などが利用できる。FIG. 6 is a schematic diagram of an example in which the present invention is applied to oscillation wavelength control of an excimer laser. In FIG. 6, a part of the laser beam is guided to a wavelength detection device 62 of the present invention, which sends a signal proportional to the difference between the oscillation wavelength of the laser and the target wavelength, which is built in the excimer laser device. The oscillation wavelength is controlled by sending it to a mechanism 61b that changes the oscillation wavelength. As a mechanism for changing the oscillation wavelength, a method of changing the air pressure between the gaps of the air space etalon provided in the light valve oscillator can be used.
発明者らが長期の波長安定性を試験した結果、６ケ月以
上にわたって中心波長を０．ＯＯｆｎｍ以内に保つこと
ができた。The inventors tested long-term wavelength stability and found that the center wavelength remained at 0. It was possible to maintain it within OOfnm.
本発明は、上記のような発振波長を任意の値に精密に設
定できる機構を備えたレーザ装置の実現に必要な、レー
ザ光の中心波長と目標波長との差音精密に検出する方法
として有用なものである。The present invention is useful as a method for precisely detecting the difference between the center wavelength of laser light and a target wavelength, which is necessary for realizing a laser device equipped with a mechanism that can precisely set the oscillation wavelength to an arbitrary value as described above. It is something.
発明の詳細
な説明したように、本発明によれば、レーザ光などの単
色光の中心波長の検出を、長期間にわたって精度よく行
なうことができるという、すぐれた特徴を有する波長検
出装置を提供するものである。DETAILED DESCRIPTION OF THE INVENTION As described in detail, the present invention provides a wavelength detection device having an excellent feature of being able to accurately detect the center wavelength of monochromatic light such as a laser beam over a long period of time. It is something.
第１図は本発明の一実施例を示す概略図、第２図は本発
明の異なる実施例を示す概略図、第３図は本発明の異な
る実施例の原理を示す図、第４図は本発明の第２の異な
る実施例を示す概略図、第５図は干渉縞が楕円形状を示
す場合の図、第６図はエキシマレーザ装置への応用例を
示す概略図、第７図は従来の装置を示す概略図である。
１１・・・・・・し／ズ、１２・・・・・・ファプリペ
ローエタロン、１３・・・・・・リニアイメージセンサ
、１４・・・・・・干渉縞、１５・・・・・・信号処理
器、４１・・・・・・２次元イメージセンサ、６１２Ｌ
・・・・・・エキシマレーザ発信器、６１ｂ・・・・・
・発振波長を変化させる機構、６２・・・・・・波長検
出装置。
図
（ｉｌＬｌ
１１−・−レ・７ス
／Ｚ−−ファ７すへ１０−エタロン
第２図
ｔｂ）
第
図
／４
Ｃｂ）
第
図
ζ山）
Ｃｂ）
第
図
（ユ２
第
図
１、／
／Fig. 1 is a schematic diagram showing one embodiment of the present invention, Fig. 2 is a schematic diagram showing a different embodiment of the invention, Fig. 3 is a diagram showing the principle of different embodiments of the invention, and Fig. A schematic diagram showing a second different embodiment of the present invention, FIG. 5 is a diagram in which interference fringes have an elliptical shape, FIG. 6 is a schematic diagram showing an example of application to an excimer laser device, and FIG. 7 is a conventional diagram. FIG. 11...S/Z, 12...Fapri-Perot etalon, 13...Linear image sensor, 14...Interference fringe, 15...・Signal processor, 41...Two-dimensional image sensor, 612L
...Excimer laser transmitter, 61b...
- Mechanism for changing the oscillation wavelength, 62... Wavelength detection device. Figure (ilLl 11-・-Re・7th/Z--Fa7th 10-Etalon 2nd figure tb) Figure/4 Cb) Figure ζ mountain) Cb) Figure (U2 Figure 1, / /
Claims (1)
が介在され、前記受光素子上に生じた光の干渉縞の径を
測定することにより、前記光の中心波長を検出すること
を特徴とする波長検出装置。A Fabry-Perot etalon is interposed between the imaging optical system and the light receiving element, and the center wavelength of the light is detected by measuring the diameter of interference fringes of the light generated on the light receiving element. wavelength detection device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19496788A JPH0244219A (en) | 1988-08-04 | 1988-08-04 | Wavelength detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19496788A JPH0244219A (en) | 1988-08-04 | 1988-08-04 | Wavelength detector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0244219A true JPH0244219A (en) | 1990-02-14 |
Family
ID=16333319
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19496788A Pending JPH0244219A (en) | 1988-08-04 | 1988-08-04 | Wavelength detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0244219A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02153583A (en) * | 1988-12-06 | 1990-06-13 | Mitsubishi Electric Corp | Controller for stabilizing wavelength |
| WO1991001579A1 (en) * | 1989-07-14 | 1991-02-07 | Kabushiki Kaisha Komatsu Seisakusho | Narrow-band oscillation excimer laser and wavelength detector |
| EP0459494A2 (en) * | 1990-06-01 | 1991-12-04 | Mitsui Petrochemical Industries, Ltd. | Method and apparatus for detecting wavelength of laser beam |
| JPH11289116A (en) * | 1998-02-03 | 1999-10-19 | Matsushita Electric Ind Co Ltd | Etalon evaluating method and device as well as laser oscillator |
-
1988
- 1988-08-04 JP JP19496788A patent/JPH0244219A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02153583A (en) * | 1988-12-06 | 1990-06-13 | Mitsubishi Electric Corp | Controller for stabilizing wavelength |
| WO1991001579A1 (en) * | 1989-07-14 | 1991-02-07 | Kabushiki Kaisha Komatsu Seisakusho | Narrow-band oscillation excimer laser and wavelength detector |
| EP0459494A2 (en) * | 1990-06-01 | 1991-12-04 | Mitsui Petrochemical Industries, Ltd. | Method and apparatus for detecting wavelength of laser beam |
| JPH11289116A (en) * | 1998-02-03 | 1999-10-19 | Matsushita Electric Ind Co Ltd | Etalon evaluating method and device as well as laser oscillator |
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