JPS5940133A - Fourier transform spectrophotometer - Google Patents
Fourier transform spectrophotometerInfo
- Publication number
- JPS5940133A JPS5940133A JP15104382A JP15104382A JPS5940133A JP S5940133 A JPS5940133 A JP S5940133A JP 15104382 A JP15104382 A JP 15104382A JP 15104382 A JP15104382 A JP 15104382A JP S5940133 A JPS5940133 A JP S5940133A
- Authority
- JP
- Japan
- Prior art keywords
- scanning mirror
- moving speed
- fourier transform
- error
- interferogram
- 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
- 230000010354 integration Effects 0.000 claims abstract description 5
- 238000001514 detection method Methods 0.000 claims 1
- 238000005259 measurement Methods 0.000 abstract description 7
- 230000005856 abnormality Effects 0.000 abstract description 2
- 230000002401 inhibitory effect Effects 0.000 abstract 1
- 238000005070 sampling Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 238000001228 spectrum Methods 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
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/28—Investigating the spectrum
- G01J3/45—Interferometric spectrometry
- G01J3/453—Interferometric spectrometry by correlation of the amplitudes
- G01J3/4535—Devices with moving mirror
Abstract
Description
【発明の詳細な説明】
本発明は走査鏡連続走査型のフーリエ変換分光光度計に
関する。連続走査型のフーリエ変換分光器は走査鏡を連
続的に移動させることによって走査を行い、走査を繰返
して毎回測定されるインターフェログラムを積算するこ
とにより測定のＳ／Ｎ比を高よるようにしている。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous scanning mirror Fourier transform spectrophotometer. Continuous scanning Fourier transform spectrometers perform scanning by continuously moving a scanning mirror, and increase the S/N ratio of measurements by repeating scanning and integrating the interferograms measured each time. ing.
連続走査型のフーリエ分光光度計では被測定光の他に一
定波長の単色光を入射させてその光の干渉縞を測定する
ことにより得られる交流信号に基いてサンプリングパル
スを発生させ測光出力のサンプリングを行うようにして
いるので、インターフェログラムのデータは走査鏡が上
記一定波長の光の半波長分を移動する毎にサンプリング
され、従って走査鏡の移動速度の変動が測定結果に影響
することはない筈であるが、実際にはサンプリングパル
スが発せられてから測定値のサンプリング′が終る迄の
間には回路特性によって決まる一定時間のおくれがあシ
、そのため走査鏡の移動速度が異ると実際のサンプリン
グ点も異ることにな９、走査鏡の移動速度が異るとイン
ターフェログラムを構成している成分信号の周波数が一
斉にずれるが、測光回路は周波数特性を有するため成分
信号の周波数がずれると、各波長に対する見掛上の感度
が変化することになる等の影響があって、走査鏡の移動
速度のゆらぎを補償しないま＼で、インターフェログラ
ムからスペクトルを求めるとゴーストが現われると云う
問題があった。In a continuous scanning Fourier spectrophotometer, in addition to the light to be measured, monochromatic light of a certain wavelength is incident, and the interference fringes of that light are measured.Sampling pulses are generated based on the AC signal obtained, and the photometric output is sampled. Therefore, the interferogram data is sampled every time the scanning mirror moves half a wavelength of light of the above-mentioned fixed wavelength, so fluctuations in the scanning mirror's moving speed will not affect the measurement results. However, in reality, there is a certain time lag determined by the circuit characteristics between when the sampling pulse is emitted and when the sampling of the measured value is completed, so if the scanning mirror's moving speed differs, The actual sampling points will also be different9, and if the moving speed of the scanning mirror is different, the frequencies of the component signals that make up the interferogram will shift all at once, but since the photometric circuit has frequency characteristics, the frequency of the component signals If the frequency shifts, the apparent sensitivity to each wavelength will change, and ghosts will appear if the spectrum is obtained from the interferogram without compensating for fluctuations in the scanning mirror's moving speed. There was a problem that appeared.
本発明は連続走査型フーリエ変換分光器の走査鏡の移動
速度のゆらぎに対して一つの対策を提供しようとするも
のである。The present invention attempts to provide a measure against fluctuations in the moving speed of a scanning mirror in a continuous scanning Fourier transform spectrometer.
フーリエ変換分光器は干渉計に一定波長の元側られる交
流信号を用いてインターフェログラムを測定するだめの
サンプリング信号を得ている。本発明はこの一定波長の
光の干渉縞の測定によって得られる交流信号の周期を一
周期毎にモニターして走査鏡の移動速度の誤差が許容範
囲に収まっているか否かを検知し、速度誤差が許容範囲
を超えた場合はそのときのインターフェログラムの測定
データを排除してインターフェログラムの積算比加えな
いようにするものである。A Fourier transform spectrometer uses an alternating current signal of a certain wavelength to be input to an interferometer to obtain a sampling signal for measuring an interferogram. The present invention monitors the cycle of the alternating current signal obtained by measuring the interference fringes of light of a constant wavelength every cycle, detects whether the error in the moving speed of the scanning mirror is within an allowable range, and detects whether the error in the moving speed of the scanning mirror is within an allowable range. If the value exceeds the permissible range, the interferogram measurement data at that time is excluded and is not added to the interferogram integration ratio.
本発明によるときは走査鏡の移動速度の誤差が許容範囲
内にあるか否かが常にチェックされて走査鏡移動速度の
異常が検出されたときはその回の走査による測定データ
の積算が行われないのでＳ／Ｎ比の良いインターフェロ
グラムを得ることができる。According to the present invention, it is constantly checked whether the error in the moving speed of the scanning mirror is within the allowable range, and when an abnormality in the moving speed of the scanning mirror is detected, the measurement data from that scan is integrated. Therefore, an interferogram with a good S/N ratio can be obtained.
次に実施例によって本発明を説明する。第１図はマイケ
ルソン干渉計を用いたフーリエ変換型分光器を示す。Ｂ
はビームスプリッタ、Ｍは固定鏡でＳＭが走査鏡である
。Ｓは被測定光の光源でＬはＨｅ−Ｈｅレーザであシ、
Ｄｌは干渉計から出射するＨｅ−Ｈｅレーザの光を検出
する光検出器、Ｄ２は干渉計から出射する被測定光を検
出する光検出器である。走査鏡ＳＭを矢印方向に駆動す
ると光検出器Ｄ１の出力は走査鏡のＨｅ−Ｎｅレーザ光
の半波長分の移動毎に一周期の変化を行い、第２図Ａに
示すような交流成分を含んだものとなる。この交流波形
は横軸を走査鏡ＳＭの移動距離として記録すると１■θ
−Ｎｅレーザ光の半波長λ／２を一周期とする一定周期
の波形であるが、横軸を時間にすると、走査鏡ＳＭの移
動速度を■とするときＴ−（λ／２）／Ｖを一周期とし
、■の変動によってＴが変動する。この第２図Ａの波形
のゼロクロス点を検出してサンプリング信号とし、光検
出器Ｄ２の出力をサンプリングすることによシ被測定光
のインターフェログラムの測定がなされる。Next, the present invention will be explained by examples. FIG. 1 shows a Fourier transform spectrometer using a Michelson interferometer. B
is a beam splitter, M is a fixed mirror, and SM is a scanning mirror. S is the light source of the light to be measured, L is a He-He laser,
Dl is a photodetector that detects the He-He laser light emitted from the interferometer, and D2 is a photodetector that detects the measured light emitted from the interferometer. When the scanning mirror SM is driven in the direction of the arrow, the output of the photodetector D1 changes one cycle every time the scanning mirror moves by a half wavelength of the He-Ne laser beam, and produces an alternating current component as shown in Fig. 2A. It is included. This AC waveform is 1■θ when the horizontal axis is recorded as the moving distance of the scanning mirror SM.
- It is a waveform with a constant period, with one period being half wavelength λ/2 of the Ne laser beam.If the horizontal axis is time, then T-(λ/2)/V is the moving speed of the scanning mirror SM. is one period, and T changes depending on the fluctuation of ■. The interferogram of the light to be measured is measured by detecting the zero-crossing point of the waveform shown in FIG. 2A and using it as a sampling signal, and sampling the output of the photodetector D2.
本発明は光検出器Ｄ１によって得られる第２図Ａの交流
波形を波形整形してこの交流の一周期の約５０％をデユ
ーティサイクルとする矩形波信号を得、そのパルス幅を
高い周波数のクロックパルスを用いて測定することにょ
シ走査鏡ＳＭの移動速度を検出し、これを基準速度と比
較して速度誤差を求め、この速度誤差が許容範囲内にあ
るが否かを判定するように構成されている。即ち第１図
でＷは波形整形回路で、光検出器Ｄ１によって得られる
第２図Ａの交流波形を整形し、第２図Ｂに示すように交
流の正の半波に対応する矩形波信号ち
を出力する。１は発振器でｌｉＯＭＨ２のクロックパル
スを発生している。Ｇはゲート回路で波形整形回路Ｗの
出力である第２図Ｂの矩形波によって開かれ、上記クロ
ックパルスをカウンタ２に入力させる。第２図Ａの交流
波形の一周期の間においてゲート回路Ｇが開いている間
のカウンタ２の計数出力は第２図Ｂの矩形波の一個の幅
に対応しており、この計数出力がコンピュータ３に送ら
れる。In the present invention, the AC waveform of FIG. 2A obtained by the photodetector D1 is waveform-shaped to obtain a rectangular wave signal whose duty cycle is about 50% of one period of this AC, and the pulse width is changed to a high frequency. The moving speed of the scanning mirror SM is measured using clock pulses, and this is compared with a reference speed to obtain a speed error, and it is determined whether or not this speed error is within an allowable range. It is configured. That is, in FIG. 1, W is a waveform shaping circuit that shapes the AC waveform in FIG. output. 1 is an oscillator that generates clock pulses for liOMH2. G is a gate circuit which is opened by the rectangular wave shown in FIG. The counting output of the counter 2 while the gate circuit G is open during one cycle of the AC waveform in FIG. 2A corresponds to the width of one rectangular wave in FIG. 2B, and this counting output is Sent to 3.
コンピュータ３ではその計数値を基準値と比較して速度
誤差を求め、この速度誤差が許容範囲内にあるか否かを
判定する。この判定動作は第２図Ａの交流信号の一周期
毎に行われるので、走査鏡の移動速度のモニタは実際上
連続的に行われていることになる。コンピュータ３は走
査鏡の移動速度の誤差が許容範囲を超えていると判定し
たときはその回の走査によって測定されたデータをイン
ターフェログラムの積算から除外する処置をとる。The computer 3 compares the counted value with a reference value to obtain a speed error, and determines whether this speed error is within an allowable range. Since this determination operation is performed every cycle of the AC signal shown in FIG. 2A, the monitoring of the moving speed of the scanning mirror is actually performed continuously. When the computer 3 determines that the error in the moving speed of the scanning mirror exceeds the permissible range, it takes steps to exclude the data measured by that scan from the interferogram integration.
第２図Ｂの矩形波の幅を測定するのには上述実施例のよ
うにクロックパルスを計数する代りに第３図に示すよう
に周波数電圧変換器ＦＶを用いて走査鏡の移動速度に対
応する電圧信号を得、との電圧をコンパレータＣｕ、Ｃ
Ｉによって上限値ＶＵ及び下限値Ｖ／と比較し、この上
下限電圧から外れたとき、その回の測定データを廃棄す
るようにしてもよい。To measure the width of the rectangular wave shown in FIG. 2B, instead of counting clock pulses as in the above embodiment, a frequency-to-voltage converter FV is used as shown in FIG. 3 to correspond to the moving speed of the scanning mirror. Obtain a voltage signal of and compare the voltage with comparator Cu,C
I may be compared with the upper limit value VU and the lower limit value V/, and when the voltage deviates from the upper and lower limit voltages, the measurement data for that time may be discarded.
第１図は本発明の一実施例の構成を示すブロック図、第
２図は上記実施例の回路動作を示すタイムチャート、第
３図は本発明の他の実施例の要部構成を示すブロック図
である。
Ｌ・・・Ｈｅ−Ｎｅレーザ、Ｓ・・・被測定光光源、Ｂ
・・・ビームスプリッタ、Ｍ・・・固定鏡、ＥＩＭ・・
・走査鏡、Ｄｌ・・・Ｈｅ−Ｎｅレーザの光を検出する
光検出器、Ｄ２・・・被測定光を検出する光検出器。
代理人 弁理士 縣 浩 介Fig. 1 is a block diagram showing the configuration of one embodiment of the present invention, Fig. 2 is a time chart showing the circuit operation of the above embodiment, and Fig. 3 is a block diagram showing the main part configuration of another embodiment of the present invention. It is a diagram. L: He-Ne laser, S: light source to be measured, B
...beam splitter, M...fixed mirror, EIM...
・Scanning mirror, Dl... A photodetector that detects the light of the He-Ne laser, D2... A photodetector that detects the light to be measured. Agent Patent Attorney Kosuke Agata
Claims (2)
射させて得られる干渉縞の測定により ？！）られる交
流信号の周期を一周期毎に検出して所定範囲内にあるか
否かをチェックし、上記周期が所定範囲から外れている
ことが検出されたとき、その回の走査ｌ走査によって得
られたデータをインターフェログラムの積算から除外す
るようにしたフーリエ変換分光光度計。(1) By measuring the interference fringes obtained by inputting monochromatic light of a certain wavelength into a Fourier transform spectrometer. ! ) is detected every cycle to check whether it is within a predetermined range, and when it is detected that the above cycle is outside the predetermined range, the period obtained by scanning A Fourier transform spectrophotometer that excludes the captured data from the interferogram integration.
交流信号の一周期毎の周期検出手段が、同交流信号の正
又は負の半サイクルの時間幅を測定するものである特許
請求の範囲第１項記載のフーリエ変換分光光度計。(2) A patent claim in which the period detection means for each cycle of an AC signal obtained by measuring interference fringes of monochromatic light of a constant wavelength measures the time width of a positive or negative half cycle of the AC signal. A Fourier transform spectrophotometer according to scope 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15104382A JPS5940133A (en) | 1982-08-30 | 1982-08-30 | Fourier transform spectrophotometer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15104382A JPS5940133A (en) | 1982-08-30 | 1982-08-30 | Fourier transform spectrophotometer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS5940133A true JPS5940133A (en) | 1984-03-05 |
Family
ID=15510046
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15104382A Pending JPS5940133A (en) | 1982-08-30 | 1982-08-30 | Fourier transform spectrophotometer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5940133A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6161432U (en) * | 1984-09-28 | 1986-04-25 | ||
| JPS6184505U (en) * | 1984-11-06 | 1986-06-04 | ||
| JPH0359427A (en) * | 1989-07-27 | 1991-03-14 | Shimadzu Corp | Double beam system spectrophotometer |
| JP2003011704A (en) * | 2001-07-03 | 2003-01-15 | Nissan Motor Co Ltd | Seat drive controller for vehicle |
| JP2013019833A (en) * | 2011-07-13 | 2013-01-31 | Shimadzu Corp | Interference spectrophotometer |
| US9417130B2 (en) | 2014-01-07 | 2016-08-16 | Shimadzu Corporation | Interference spectrophotometer that corrects light intensity information using mirror velocity information |
| US10365159B2 (en) * | 2015-02-02 | 2019-07-30 | Foss Analytical A/S | Spectrometer system and a method for compensating for time periodic perturbations of an interferogram generated by the spectrometer system |
-
1982
- 1982-08-30 JP JP15104382A patent/JPS5940133A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6161432U (en) * | 1984-09-28 | 1986-04-25 | ||
| JPS6184505U (en) * | 1984-11-06 | 1986-06-04 | ||
| JPH0359427A (en) * | 1989-07-27 | 1991-03-14 | Shimadzu Corp | Double beam system spectrophotometer |
| JP2003011704A (en) * | 2001-07-03 | 2003-01-15 | Nissan Motor Co Ltd | Seat drive controller for vehicle |
| JP2013019833A (en) * | 2011-07-13 | 2013-01-31 | Shimadzu Corp | Interference spectrophotometer |
| US9417130B2 (en) | 2014-01-07 | 2016-08-16 | Shimadzu Corporation | Interference spectrophotometer that corrects light intensity information using mirror velocity information |
| US10365159B2 (en) * | 2015-02-02 | 2019-07-30 | Foss Analytical A/S | Spectrometer system and a method for compensating for time periodic perturbations of an interferogram generated by the spectrometer system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3319515A (en) | Interferometric optical phase discrimination apparatus | |
| JP4868477B2 (en) | Apparatus for processing the output signal of a Michelson type interferometer used in Fourier transform spectroscopy and a method for processing the output signal of a Michelson type interferometer | |
| CN110207733B (en) | Optical fiber interferometer arm length difference measuring device and method based on sweep frequency laser | |
| CN111522018B (en) | Double-femtosecond laser frequency comb distance measuring device and method | |
| CN112241014A (en) | Method and system for eliminating aliasing of dual-optical-comb frequency spectrum | |
| US4222667A (en) | Fizeau fringe light evaluator and method | |
| JPS5940133A (en) | Fourier transform spectrophotometer | |
| US6462823B1 (en) | Wavelength meter adapted for averaging multiple measurements | |
| JPH1090065A (en) | Data processor and data processing method for fourier transform spectrometer | |
| JPH03202728A (en) | Interference spectrophotometer | |
| JPH05231939A (en) | Step scan fourier transferm infrared spectral apparatus | |
| CN102095498A (en) | High-accuracy Fourier transformation measuring method of scanning type | |
| US4449823A (en) | Device for measurement of the spectral width of nearly monochromatic sources of radiant energy | |
| JPH02102425A (en) | Optical path difference zero point detecting device and optical interference signal averaging processor using same | |
| US20030058452A1 (en) | Signal modulation compensation for a wavelength meter | |
| KR0168444B1 (en) | Sample evaluating method by using thermal expansion displacement | |
| JP2758556B2 (en) | Optical signal detector | |
| JPS61246607A (en) | Measuring method for film thickness | |
| JPH0755418A (en) | Displacement gauge | |
| JPS61501876A (en) | Sample signal generator and method for interferogram | |
| JPH02307027A (en) | Light frequency measuring instrument | |
| JPH0346523A (en) | Signal processor for fourier-transformation type spectroscope | |
| JPH06147853A (en) | Reflectometer | |
| CN113281296A (en) | Terahertz detector absolute spectral response calibration device and calibration method | |
| Lacourt et al. | Longitudinal Analysis of the Complex Transmittance of Optical Pupils by Spectral Modulation of White Light |