JPS62245120A - Cars spectroscopic apparatus - Google Patents

Abstract

PURPOSE:To obtain a CARS spectroscopic apparatus having high detection sensitivity and hard to generate the shift of a light path, by using a Perrin- Blocha prism and bringing two kinds of exciting laser beams having different wavelengths to parallel beams holding a minute gap therebetween. CONSTITUTION:A part of laser beam 2 is divided by a half-mirror 3 to be inputted to a Stokes-Raman vibration frequency wavelength oscillation laser 4 and the beam transmitted through the mirror 3 is incident to a Perrin-Blocha prism 6 to be emitted to a direction almost 90 deg. to the incident direction. The long wavelength laser beam 7 emitted from the laser 4 is incident to the prism 6 at a required angle from a predetermined position to be emitted as parallel beam separated from the beam 2 by a minute gap of 1mm or less. These emitted beams 2, 7 are condensed by a condensing lens 8 to cross each other at a minute angle of 1 deg. or less in a specimen cell 9. The anti-Stokes-Raman beam 11 emitted from the condensing/crossing part in the cell 9 and the beams 2, 7 are returned to parallel beams to receive wavelength dispersion. The beam 11 is taken out from a pinhole 13 to be introduced into a spectroscope 14 to be separated from backlight caused by the beams 2, 7 and detected to be amplified by an amplifier 15 to be recorded on a recorder 16.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明はカース分光ｆｃｉｌｌに係り、特に、２種の励
起レーザ光を微小角交差させるのに好適なカース分光装
置に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a Kerse spectroscopy fcell, and particularly to a Kerse spectrometer suitable for causing two types of excitation laser beams to intersect at a small angle.

〔従来の技術〕[Conventional technology]

従来のカース分光装置は、例えば特開昭５９−６１７５
８号公報に記載されている様に、２ｆｌＪ！［の励起レ
ーザ光の一方をダイククイックミラーで反射させ、他方
を透過させることにより、２橿の励起レーザ光を微小距
離はなれた平行光とし、これを凸レンズで集光させて被
測定′＠質が元項された系内で微小角交差させている。A conventional Kerse spectrometer is, for example, disclosed in Japanese Patent Application Laid-Open No. 59-6175.
As stated in Publication No. 8, 2flJ! By reflecting one of the excitation laser beams with a Dyck quick mirror and transmitting the other, the two excitation laser beams are made into parallel beams separated by a minute distance, and this is condensed by a convex lens to obtain the material to be measured. are intersected at a small angle in a system in which the elements are elements.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

カース分光装置では、励起に用いる２４ｔＥのレーザ光
の波長差が最大１５０１Ｌ％程度であり、非常に接近し
ている。このため、各々のレーザ光を透過あるいは反射
するダイククイックミラーの特性は、各々のレーザ光を
１００％透過もしくは反射する事が望ましい。しかし、
実際のダイククイックミラーはレーザ光を一部吸収し、
入射光の３〜５割程度の損失が生じるため、カース分光
装置の構出感度は理論値の５割以下罠低下してしまうと
いう問題がある。In the Kaas spectrometer, the maximum wavelength difference between the 24tE laser beams used for excitation is about 1501L%, which is very close. Therefore, it is desirable that the characteristic of the dike quick mirror that transmits or reflects each laser beam is to transmit or reflect 100% of each laser beam. but,
The actual Dyke quick mirror absorbs some of the laser light,
Since a loss of about 30 to 50% of the incident light occurs, there is a problem in that the configuration sensitivity of the Curse spectrometer is reduced to less than 50% of the theoretical value.

また、カース分−３’ｅ、装置では２ａ［のレーザ光の
果光・交差部からのみ被測定物質の反ストークスラマン
光が生ずるため高い位置分解能が得られるが、反ストー
クスラマン元強度は励起レーザ光の交差角に指数型に依
存し、角度が１°を超えると１桁以上強度低下を起こす
ことが知られている。１°以内の交差角は、平行な２種
の励起レーザ光の間隔を０．５　ｍｍ程度以下とし、凸
レンズで集光することにより初めて実現される。ところ
が、ダイクロイックミラーを用いた場合、ダイクロイッ
クミラー内部での屈折現象に基き、１ｒｒＬｍ程度の光
路すれが光学系の位置変動により生じてしまい、調整が
難しいという問題もある。In addition, the anti-Stokes Raman light of the measured substance is generated only from the fruit light/intersection of the laser beam of 2a[ in the device with the Kerse component -3'e, so high positional resolution can be obtained, but the anti-Stokes Raman original intensity is It is known that it depends on the intersection angle of the laser beam in an exponential manner, and that when the angle exceeds 1°, the intensity decreases by more than one order of magnitude. A crossing angle of 1° or less can only be achieved by setting the distance between two parallel excitation laser beams to about 0.5 mm or less and focusing the beams with a convex lens. However, when a dichroic mirror is used, there is a problem that optical path deviation of about 1 rrLm occurs due to positional fluctuations of the optical system due to refraction phenomena inside the dichroic mirror, making adjustment difficult.

本発明の目的は、検出感度が高（、光学系の位置を変動
しても光路ずれが起きに（いカース分光装置を提供する
ことにある。An object of the present invention is to provide a Kaas spectrometer that has high detection sensitivity (and does not cause optical path deviation even if the position of the optical system is changed).

〔問題点を解決するための手段〕[Means for solving problems]

上記問題点は、ダイクロイックミラーの代りに。 The above problems can be solved by using a dichroic mirror instead.

ペランブロカプリズムを使用して２種の波長の異なる励
起レーザ光を微小間隔保った平行光とすることにより解
決される。This problem can be solved by using a Perambroca prism to convert two types of excitation laser beams with different wavelengths into parallel beams with a small distance between them.

〔作用〕[Effect]

５つの辺を有するペラン・プロカブリズムの最長・辺を
有する面に所定の角度で発振波長固定の第１の励起レー
ザ光を入射させると、幻応した出射面から、入射面に対
し″″Ｃ略９０°方向に第１の励起レーザ光が出射する
。さらに第１のレーザで励起された第２の長波長励起レ
ーザｔｙｒ、第１のレーザ光より低分散側すなわち出射
面に近い側から所定の角度で入射させると、第１のレー
ザ光と同一出射面から、第１のレーザ光と平行に第２の
励起レーザ光が出射する。第１と第２のレーザ光の入射
面への入射点間隔を移動させる墨により、第１と第２の
レーザ光を所要の微小間隔に保った平行光として得られ
る。When the first excitation laser beam with a fixed oscillation wavelength is incident at a predetermined angle on the longest side surface of the Perrin Procabulism, which has five sides, from the phantom exit surface to the input surface, ``'' C The first excitation laser beam is emitted in a direction of approximately 90°. Furthermore, when the second long wavelength excitation laser tyr excited by the first laser is incident at a predetermined angle from the lower dispersion side than the first laser beam, that is, from the side closer to the emission surface, the same output as the first laser beam is emitted. A second excitation laser beam is emitted from the surface in parallel to the first laser beam. By moving the interval between the incident points of the first and second laser beams on the incident surface, the first and second laser beams are obtained as parallel beams with a required minute interval maintained.

このペラン・プロカブリズムでは各々のレーザ光の吸収
は生じず、入射面でのレーザ光の反射も少ないため、効
率良く第１および第２のレーザ光を被測定物質に照射で
きる。またペラン・プロカブリズム内での全反射を用い
て光路合わせな行うため稟１と、ｉｇ２のレーザの、透
過物買の屈折による光路ずれも生じない。In this Perrin-procabulism, absorption of each laser beam does not occur and there is little reflection of the laser beam on the incident surface, so the first and second laser beams can be efficiently irradiated onto the substance to be measured. In addition, since the optical paths are aligned using total reflection within the Perrin Procabulism, there is no optical path deviation due to refraction of the transmitted objects of the 1 and 2 lasers.

〔実施例〕〔Example〕

以下、本発明の一実施例を図面を参照して説明するＯ 図は本発明の一実施例に係るカース分光装置の構成図で
ある。図において、１は発振波長固定のパルスレーザで
あり、パルスレーザ１から発振されたレーザ光２は一部
か−・−７ミラー３で分割され、ストークスラマン撮動
数彼長発振レーザ４の励起に用いられる。ノ・−フミラ
ー３を透過したレーザ光２は、ミラー５，５′により進
路が変えられ、ペランブロカプリズム６の最長辺を有す
る面に入射される。ペランブロカプリズム６はミラー５
′から入射してくるレーザ光に対して所要の角度に設定
されており、該レーザ光は内部で全反射した後、入射方
向と略９０°方向に出射される。一方、レーザ４から射
出された長波長のレーザ光７は、ペランブロカプリズム
６のレーザ光２０入射位置より低分散側である出射面に
近い側の最長辺を有する面からＦｆｒＯの角度で入射さ
れ、レーザ光２と１ｍｍ以下の微小距離はなれた平行光
としてペランブロカプリズム６から出射する。Hereinafter, one embodiment of the present invention will be described with reference to the drawings. The drawing is a configuration diagram of a Kerse spectrometer according to one embodiment of the present invention. In the figure, 1 is a pulsed laser with a fixed oscillation wavelength, and part of the laser beam 2 emitted from the pulsed laser 1 is split by a mirror 3, which excites the long oscillation laser 4 with a Stokes Raman imaging number. used for. The course of the laser beam 2 transmitted through the nof mirror 3 is changed by mirrors 5 and 5', and is incident on the surface of the Perambroca prism 6 having the longest side. Perambroca prism 6 is mirror 5
The laser beam is set at a required angle with respect to the laser beam that enters from the inside, and after being totally reflected inside, the laser beam is emitted in a direction approximately 90 degrees from the direction of incidence. On the other hand, the long-wavelength laser beam 7 emitted from the laser 4 enters the Perambroca prism 6 at an angle of FfrO from the surface having the longest side on the side closer to the emission surface, which is on the lower dispersion side than the laser beam 20 incident position of the Perambroca prism 6. , is emitted from the Perambroca prism 6 as parallel light separated from the laser light 2 by a minute distance of 1 mm or less.

ペランブロカプリズム６から出射した平行レーザ光２，
７は、凸レンズ８により集光され、試料セル９中で１°
以内の微小な角度で交差する。試料セル９中の集光・交
差部から発生した反ストークスラマン光１１及びレーザ
光２，７は、凸レンズ１０により平行光に戻され、分散
用プリズム１２で波長分散される。そして、ピンホール
１３によって反ストークスラマン光１１が取り出され、
分光器１４に導入されてレーザ光２，７に起因する迷光
と分離された後、光検出器１５で検出・増幅され、記録
計１６に記録される。Parallel laser beam 2 emitted from Peranbroca prism 6,
7 is focused by a convex lens 8 and is focused at 1° in a sample cell 9.
intersect at a minute angle within The anti-Stokes Raman light 11 and the laser lights 2 and 7 generated from the condensing/intersecting part in the sample cell 9 are returned to parallel light by the convex lens 10 and wavelength-dispersed by the dispersion prism 12. Then, the anti-Stokes Raman light 11 is extracted through the pinhole 13,
After being introduced into the spectrometer 14 and separated from stray light caused by the laser beams 2 and 7, the light is detected and amplified by the photodetector 15 and recorded on the recorder 16.

〔発明の効果〕 本発明によれば、従来のｂ以下の光損失で励起用の２棟
のレーザ光を微小間隔で平行光線として精度よ（貞ね合
せるので、検出感度を２倍以上向上でき、また１°以内
の微小な交差角を安定に保てるため、党略変動に起因す
る検出光強度変動を小さくできる効果がある。[Effects of the Invention] According to the present invention, since the two laser beams for excitation are made into parallel beams with a minute interval and the optical loss is less than the conventional one, the detection sensitivity can be improved by more than double. In addition, since a small crossing angle of 1° or less can be stably maintained, it is possible to reduce fluctuations in detected light intensity caused by random fluctuations.

【図面の簡単な説明】[Brief explanation of drawings]

図は、本発明の一実施例に係るカース分光装置の構成図
である。 １・・・全県波長固定レーザ ２Ｉ７°・・レーザ光　　　３・・・ノ１−７ミラー４
・・・ストークスラマン振動数波長発振レーザ５Ｔ５′
・・・ミラー ６・・・ペラン・プロカブリズム ８ツ１０・・・レンズ　　　　９・・・試料セル１１・
・・反ストークスラマン元 １２・・・分散用プリズム　　１３・・・ピンホール１
４・・・分光器　　　　　　１５・・・検出器１６・・
・記録計The figure is a configuration diagram of a Curse spectrometer according to an embodiment of the present invention. 1...All prefecture wavelength fixed laser 2I7°...Laser light 3...No1-7 mirror 4
...Stokes Raman frequency wavelength oscillation laser 5T5'
...Mirror 6...Perrin Procabulism 8 pieces 10...Lens 9...Sample cell 11...
...Anti-Stokes Raman element 12...Dispersion prism 13...Pinhole 1
4... Spectrometer 15... Detector 16...
・Recorder

Claims (1)

【特許請求の範囲】[Claims] １、波長一定のレーザ光と、該レーザ光により励起され
試料のストークスラマン振動数に一致した波長のレーザ
光とを微小間隔離れた平行光線とし、該平行光線を凸レ
ンズを介して試料に入射し、両レーザ光の集光交差部か
ら射出される試料の反ストークスラマン光を検出するカ
ース分光装置において、ペランブロカプリズムの最長辺
を有する面に前記両レーザ光を夫々波長に応じた所要の
入射角で入射させて前記平行光線を該ペランブロカプリ
ズムから出射させることを特徴とするカース分光装置。1. A laser beam with a constant wavelength and a laser beam excited by the laser beam with a wavelength that matches the Stokes Raman frequency of the sample are made into parallel rays separated by a minute interval, and the parallel rays are incident on the sample through a convex lens. In a Kars spectrometer that detects the anti-Stokes Raman light of a sample emitted from the condensing intersection of both laser beams, the two laser beams are incident on the longest side of the Perambroca prism at a required angle of incidence according to the respective wavelengths. A Kaas spectroscopic device characterized in that the parallel light beam is made incident at an angle and then emitted from the Perambroca prism.