JP3213250B2 - Optical measurement device - Google Patents

Optical measurement device

Info

Publication number
JP3213250B2
JP3213250B2 JP01554497A JP1554497A JP3213250B2 JP 3213250 B2 JP3213250 B2 JP 3213250B2 JP 01554497 A JP01554497 A JP 01554497A JP 1554497 A JP1554497 A JP 1554497A JP 3213250 B2 JP3213250 B2 JP 3213250B2
Authority
JP
Japan
Prior art keywords
light
signal
optical
phase
beam
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
Application number
JP01554497A
Other languages
Japanese (ja)
Other versions
JPH10213485A (en
Inventor
キンプイ チャン
耕自 佐鳥
Original Assignee
株式会社生体光情報研究所
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 株式会社生体光情報研究所 filed Critical 株式会社生体光情報研究所
Priority to JP01554497A priority Critical patent/JP3213250B2/en
Publication of JPH10213485A publication Critical patent/JPH10213485A/en
Application granted granted Critical
Publication of JP3213250B2 publication Critical patent/JP3213250B2/en
Anticipated expiration legal-status Critical
Application status is Expired - Lifetime legal-status Critical

Links

Description

【発明の詳細な説明】 DETAILED DESCRIPTION OF THE INVENTION

【0001】 [0001]

【発明の属する技術分野】本発明は、被検体にコヒーレント光を照射しその被検体を経由透過あるいは反射した光を利用してその被検体の光計測を行なう光計測装置に関する。 The present invention relates to relates to an optical measurement device for optical measurement of the subject by using light passing through transmitted or reflected by the subject is irradiated with coherent light to the subject.

【0002】 [0002]

【従来の技術】人体やその他の生体組織のような、光に対して顕著な光散乱体を被検体とする光計測の最大の難点は、被検体から四方八方に出射する透過光あるいは反射光のうち追跡が可能な光路に沿った光をどのようにして抽出するかということにある。 Such as human or other biological tissues, the largest drawback of optical measurement of the subject significant light scatterers to light is transmitted or reflected light is emitted in all directions from the subject It lies in the fact that how the extracts the light along the optical path capable of tracking of. これを可能にする方法として、例えば極めて短いレーザパルス(ピコ秒;10 As a method to make this possible, for example, very short laser pulses (picosecond; 10
-12 sec程度のレーザパルス)を被検体に入射して、 About -12 sec of the laser pulse) is incident on the object,
その出射光の時間プロファイルを超高速ストリックカメラを用いて測定し、最短距離を通過した光成分、すなわち、見かけ上の透過直進光成分を抽出する方法が知られている(例えばS.Anderson−Engele The time profile of the emitted light was measured using an ultra-fast Strick camera, light components passing through the shortest distance, i.e., a method of extracting the transmitted straight light components of the apparent is known (e.g. S.Anderson- Engele
s, R. s, R. Berg, S. Berg, S. Svanberg, O. Svanberg, O.
Jarlman ”Optics Letters” Jarlman "Optics Letters"
vol. vol. 15,1179(1990)参照。 15,1179 (1990). )一方、散乱光の方向性の消失に着目し、アンテナ特性として知られている優れた方向選択性を持つ光ヘテロダイン検出法を用いて、方向性を保った透過直進光成分および近軸前方散乱光成分のみを検出する方法も提案されている(例えば、M.Toida, M.Kondo, T.Ic ) On the other hand, paying attention to the loss of directionality of the scattered light, by using the optical heterodyne detection method with excellent direction selectivity known as antenna characteristics, transmitted straight light component keeping the directionality and the paraxial forward scatter method of detecting only the light components has been proposed (e.g., M.Toida, M.Kondo, T.Ic
himura, H. himura, H. Inaba ”Electron Inaba "Electron
ic Letters” vol.26,700(19 ic Letters "vol.26,700 (19
90)参照)。 90) reference).

【0003】光ヘテロダイン検出法に基づく光計測は、 [0003] The optical measurement based on optical heterodyne detection method,
本質的には、散乱を受けながらも前進して、入射光の時間コヒーレンス性を一部保持したまま散乱体から出射する光信号を選択的に検出するという特徴をもつことも指摘されている(例えば、K.P.Chan, M.Ya In essence, while being scattered even advanced, it has been pointed out to have a characteristic of selectively detecting optical signals exiting the temporal coherence of the incident light from the left scatterer was partially retained ( For example, K.P.Chan, M.Ya
mada, H. mada, H. Inaba ”Applied Ph Inaba "Applied Ph
ysics” B, vol.63,249(199 ysics "B, vol.63,249 (199
6)参照)。 6) reference).

【0004】さらに、光ヘテロダイン検出法に基づく光計測の高速化と高分解能を図るために、透過光を二次元的に検出する二次元光ヘテロダイン検出器アレイの導入も提案されている(K.P.Chan, M.Yama [0004] Further, in order to speed and high resolution of an optical measurement based on the optical heterodyne detection method, it has been proposed the introduction of two-dimensional optical heterodyne detector array for detecting the transmitted light in two dimensions (K. P.Chan, M.Yama
da, H. da, H. Inaba ”Electronics Inaba "Electronics
Letters” vol.30, 1753(199 Letters "vol.30, 1753 (199
4)参照)。 4) reference).

【0005】 [0005]

【発明が解決しようとする課題】ところが、光ヘテロダイン検出法は、信号光にコヒーレンス性を要求する上、 [SUMMARY OF THE INVENTION However, the optical heterodyne detection method, on requesting a coherence in the signal light,
各々の光路を辿り、このため、各々異なる光路長を有する近軸前方散乱光は受光器上に不定(ランダム)な合成位相をなし、光干渉信号の強度も不定となる。 Follows the optical path of each of the, Therefore, each different paraxial forward scattered light having an optical path length without the indefinite (random) synthesis phase on the light receiver, the intensity of the optical interference signal also becomes unstable. これはレーザスペックル現象としてよく知られている(例えば、 This is well known as laser speckle phenomenon (for example,
J. J. C. C. Dainty編”Laser Speckle Dainty ed "Laser Speckle
And Related Phenomena ”S And Related Phenomena "S
pringer−Verlag社出版(New Yor pringer-Verlag, Inc. Publishing (New Yor
k,1975)参照)。 k, 1975) reference).

【0006】図5〜図7は、レーザスペックル現象による信号強度の時間変化を示した図である。 [0006] Figures 5-7 are diagrams showing the time change of the signal intensity by the laser speckle phenomenon. 図5,図6, FIGS. 5, 6,
図7は、厚みがともに1cmの、それぞれ、じゃがいも、赤身牛肉、および鶏の胸肉に直径約400μmのレーザ光(波長1.06μm)を入射し、それぞれの試料を透過した光をヘテロダイン方式で検出したときのヘテロダイン信号強度の時間経過を示している。 7, the thickness are both 1 cm, respectively, potatoes, lean beef, and the laser beam having a diameter of about 400μm to chicken breast (wavelength 1.06 .mu.m) incident light in heterodyne system transmitted through each sample It shows the time course of the heterodyne signal intensity when detected.

【0007】これらの結果からわかるようにスペックルの時間的な変遷、すなわち、ヘテロダイン信号強度が変化する周期は試料毎に極めて大きく異なっている。 [0007] the temporal evolution of the speckle As can be seen from these results, that is, the period of the heterodyne signal intensity varies is different very large for each sample. スペックルの影響による光ヘテロダイン信号の強度分布は統計的にレーリ分布に従うことが周知であり、スペックル平均、すなわち信号強度の時間平均を行なえば、スペックルの影響を有効に解消することができることが知られている。 The intensity distribution of the optical heterodyne signal due to the influence of speckle are known to follow the statistical Rayleigh distribution, speckles average, i.e. by performing a time average of the signal intensities, it is possible to effectively eliminate the influence of the speckle It has been known. しかし、図7の例に示されるような、スペックルが統計的にランダムな状況に変化するのに約1分も要する試料の場合、独立したスペックルの多数回の平均を行なうには、かなりの長時間を要する結果となる。 However, as shown in the example of FIG. 7, if the speckles of the sample taken as about 1 minute for the change in a random situation statistically, to perform an average of multiple independent speckle considerably a long period of time will result in requiring of.

【0008】本発明は、試料によらず短時間でスペックルの影響を有効に解消することのできる光計測装置を提供することを目的とする。 [0008] The present invention aims to provide an optical measuring device that can effectively eliminate the influence of the speckle in a short time regardless of the sample.

【0009】 [0009]

【課題を解決するための手段】上記目的を達成する本発明の光計測装置は、コヒーレント光を出射する光源と、 Means for Solving the Problems An optical measuring apparatus of the present invention to achieve the above object, a light source for emitting coherent light,
被検体が配置される被検体配置部と、上記光源から出射されたコヒーレント光を、被検体配置部を経由する信号光と、被検体配置部を経由する光路とは異なる光路を経由する参照光とに二分するとともに、被検体配置部を経由した後の信号光と、異なる光路を経由した参照光とを互いに重畳することにより該信号光と該参照光とが干渉した干渉光を生成する干渉光学系と、干渉光学系で生成された干渉光を受光する受光器と、被検体配置部に達する前の信号光の光路上に配置され、信号光のビーム内を複数の領域に分割したときの各分割領域の位相を相互に異ならせるとともに、これら複数の分割領域の位相パターンを時間的に順次変化させる位相分布変調器とを備えたことを特徴とする。 And the object arrangement unit which the subject is placed, the reference light passing through the optical path different coherent light emitted from the light source, and the signal light passing through the subject placement unit, the optical path passing through the object arrangement unit with bisecting the bets, interference generates interference light the signal light and reference light Metropolitan interferes by superimposing the signal light after passing through the subject placement unit, and the reference light propagated through different optical paths from each other an optical system, a photodetector receiving the interference light produced by the interference optical system is arranged on an optical path of the signal light before reaching the subject placement unit, when dividing the inside of the beam of the signal light into a plurality of regions phase causes different from each other to the respective divided areas, characterized by comprising a phase distribution modulator sequentially changing the phase pattern of the plurality of divided regions temporally.

【0010】ここで、上記本発明の光計測装置において、上記干渉光学系は、典型的には、信号光のビーム径を拡大して上記位相分布変調器に導くものである。 [0010] Here, in the optical measuring apparatus of the present invention, the interference optical system is typically an enlarged beam diameter of the signal light and guides to the phase distribution modulator. また、上記本発明の光計測装置には、上記受光器が干渉光のビーム内を複数の領域に分割したときの各分割領域それぞれを独立に受光する、配列された複数の受光素子を有するものであってもよい。 Further, above the optical measuring apparatus of the present invention are those having the divided areas respectively for receiving independently plurality of light receiving elements arranged when the photodetector is divided within the beam of the interference light into a plurality of regions it may be.

【0011】さらに、上記本発明の光計測装置には、上記位相分布分布変調器で上記信号光の位相パターンとを順次変化させる間の上記受光器の出力を平均化する平均演算部が備えられ、ないしは接続される。 Furthermore, the the optical measuring device of the present invention, provided the average calculation unit for averaging the output of the light receiver while sequentially changing the phase pattern of the signal light by the phase distribution distribution modulator , or is connected. 本発明の光計測装置は、上記位相分布変調器を備え、入射信号光の位相パターンを順次変化させるものであり、入射信号光の位相パターンを変化させる毎にランダムなスペックルパターンが得られる。 Optical measuring apparatus of the present invention is provided with the phase distribution modulator, which sequentially changing the phase pattern of the incident signal light, a random speckle pattern is obtained for each changing the phase pattern of the incident signal light. したがって試料自体ではスペックルの変化速度が極めて遅い試料の場合であっても入射光の位相パターンを変化させる毎にスペックルパターンを変化させることができ、平均化を高速に行なうことができ、高速な光計測が可能となる。 Thus the sample itself can change the speckle pattern for each changing the phase pattern of a was also the incident light when the change rate of the speckle is very slow sample, it can be performed averaging at high speed, a high speed light measurement is made possible such.

【0012】 [0012]

【発明の実施の形態】以下、本発明の実施形態について説明する。 BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described. 図1は、本発明の光計測装置の第1実施形態の構成図である。 Figure 1 is a block diagram of a first embodiment of an optical measuring apparatus of the present invention. レーザ光源11から出射したレーザ光11aは、ビームスプリッタ12により信号光11bと参照光11cとに二分される。 Laser beam 11a emitted from the laser light source 11 is divided by the beam splitter 12 into a reference light 11c and the signal light 11b. 信号光11bは、2枚のレンズ13a,13bからなるビームエクスパンダ13 Signal light 11b includes two lenses 13a, beam expander 13 consisting 13b
によりそのビーム径が拡大されて、駆動回路141により駆動される位相分布変調器14に入射する。 The beam diameter is enlarged, and enters the phase distribution modulator 14 driven by the drive circuit 141 by. この位相分布変調器14は、詳細は後述するが、ビームエクスパンダ13によりビーム径が拡大された信号光のビーム内を複数の領域に分割した時の各分割領域の位相を相互に異ならせるとともに、それら複数の分割領域の位相パターンを時間的に順次変化させるものである。 This phase distribution modulator 14, which will be described in detail later, together with varying the phase of each divided region when dividing the inside beam signal beam diameter is enlarged light into a plurality of areas by the beam expander 13 to each other is the phase pattern of the plurality of divided regions which is temporally changed sequentially. この位相分布変調器14を経由した信号光は、被検体配置部15に配置された光散乱被検体10を透過し、ビームスプリッタ16に入力する。 Signal light passed through the phase distribution modulator 14 is transmitted through the light scattering specimen 10 disposed on the subject placement unit 15, and inputs to the beam splitter 16.

【0013】一方、ビームスプリッタ12により信号光11bとに二分された参照光11cは、ミラー18で反射し音響光学的変調器(AOM)19により周波数シフトを受け、2枚のレンズ20a,20bからなるビームエクスパンダ20によりビーム径が拡げられ、さらにミラー21で反射してビームスプリッタ16に入射する。 Meanwhile, the reference beam 11c which is bisected by the beam splitter 12 into a signal light 11b is subjected to frequency shift by the acoustic optical modulator (AOM) 19 reflected by a mirror 18, two lenses 20a, from 20b consisting beam Aix by expander 20 beam diameter is expanded, further enters the beam splitter 16 is reflected by the mirror 21.

【0014】ビームスプリッタ16には、上記のようにして、信号光と参照光との双方が入射して互いに重畳され、それら信号光と参照光が干渉した干渉光となって受光器17に入射する。 [0014] Beam splitter 16 is, as described above, both the signal light and reference light are superposed one another incident, incident on the light receiver 17 becomes interference light and reference light which signal light interferes to. 受光器17には、二次元的に配列された複数の受光素子17a,17b,…,17nが備えられており、それら複数の受光素子17a,17b, The light receiver 17 is two-dimensionally arrayed a plurality of light receiving elements 17a, 17b, ..., 17n are provided, the plurality of light receiving elements 17a, 17b,
…,17nにより、被検体10の、透過率分布を表わす複数のビート信号が生成される。 ..., by 17n, a plurality of beat signals representing the subject 10, the transmittance distribution is generated. 各受光素子17a,1 Each of the light-receiving element 17a, 1
7b,…,17nで得られるビート信号はAOM19による周波数シフト量に対応する周波数を持つ信号である。 7b, ..., the beat signal obtained by 17n is a signal having a frequency corresponding to the frequency shift amount by AOM19. 受光器17を構成する複数の受光素子17a,17 A plurality of light receiving elements 17a constituting the light receiver 17, 17
b,…,17nで得られた複数のビート信号は信号処理部22に入力され、信号処理部22では、これら複数のビート信号の信号強度により表わされる、被検体10の透過率分布が求められる。 b, ..., a plurality of beat signals obtained by 17n is input to the signal processing section 22, the signal processing section 22, represented by the signal strength of the plurality of beat signals, the transmittance distribution of the subject 10 is obtained . この透過率分布を求めるにあたっては、位相分布変調器14で信号光の位相パターンを変化させる毎にビート信号を取り込み、それら時間的に順次入力される複数の位相パターンのビート信号に基づいて、それらの間の時間平均的な透過率分布が求められ、これにより、スペックルの影響が高精度にかつ高速に取り除かれる。 When obtains the transmittance distribution, takes in the beat signal each time changing the phase pattern of the signal light phase distribution modulator 14, based on the beat signals of a plurality of phase patterns to be their temporally sequential input, they time average transmittance distribution is obtained between, thereby, the influence of the speckle is removed fast and with high accuracy. ディスプレイ23には、信号処理部2 The display 23, the signal processing section 2
2で得られた透過率分布を表わす画像が表示される。 Image representing a transmittance distribution obtained in 2 is displayed.

【0015】図2は、図1によるブロックで示す位相分布変調器14の一構成例を示す図である。 [0015] Figure 2 is a diagram showing an example of the configuration of a phase distribution modulator 14 shown in the block according to FIG. それぞれが、 Respectively,
例えば1mm×1mmの面積を持つ複数のミラー142 For example, a plurality of mirrors 142 with an area of ​​1 mm × 1 mm
a,142b,142c,…が2次元的に配列されており、各ミラー142a,142b,142c,…の背面には、各ミラー142a,142b,142c,…駆動するための圧電素子143a,143b,143c,… a, 142b, 142c, ... are two-dimensionally arranged, each mirror 142a, 142b, 142c, ... on the back of each mirror 142a, 142b, 142c, ... piezoelectric elements 143a for driving, 143b, 143c, ...
が固定されている。 There has been fixed. 駆動回路141が各圧電素子143 Drive circuit 141 each of the piezoelectric elements 143
a,143b,143c,…に電圧を印加すると電圧の印加を受けた圧電素子の厚みがその印加電圧に応じた量だけ変化し、その圧電素子が固定されたミラーがx方向に微小移動する。 a, 143b, 143c, when a voltage is applied to ... to the thickness of the piezoelectric element subjected to a voltage change amount corresponding to the applied voltage, the mirror that the piezoelectric element is fixed is slightly moved in the x direction. これらのミラー142a,142b, These mirrors 142a, 142b,
142c,…には、図1に模式的に示すように位相の揃った信号光が入射するが、駆動回路141により各圧電素子143a,143b,143c,…にそれぞれ異なる電圧を印加すると、各ミラー142a,142b,1 142c, the ..., the signal light having a uniform phase as shown schematically in Figure 1 is incident, each of the piezoelectric elements 143a by the drive circuit 141, 143b, 143c, upon application of a different voltage ..., each mirror 142a, 142b, 1
42c,…で反射した信号光は、図1に模式的に示すように、その信号光のビーム内で位相分布を持つ信号光となる。 42c, the signal light reflected by ..., as shown schematically in FIG. 1, the signal light having the phase distribution in the beam of the signal light. その位相パターンは、駆動回路141が圧電素子143a,143b,143c,…に印加する電圧パターンを変更する毎に変化する。 The phase pattern, the driving circuit 141 is a piezoelectric element 143a, 143b, 143c, varies from changing the voltage pattern to be applied to ....

【0016】図1に示す光散乱被検体10から出射した信号光には、後に実験データを示すように、もともと入射した光軸に対し、コヒーレント性をある程度保ったまま数mm程度位置ずれを生じてその光軸に対しほとんど平行に出射する近軸前方散乱光が存在し、このような近軸前方散乱光が相互に入り込むため、入射信号光の位相を、そのビーム内で例えば1mm×1mm程度の領域毎に変化させると、全く異なったスペックルパターンを伴った信号光が得られる結果となる。 [0016] The emitted signal light from the light scattering specimen 10 is shown in FIG. 1, as later it shows the experimental data, with respect to the optical axis was originally incident occurs the number of mm positional displacement while maintaining a certain degree of coherence almost parallel emitted to the optical axis there is the paraxial forward scattered light, since such paraxial forward scattered light enters the other, the phase of the incident signal light, the beam in, for example, 1 mm × 1 mm about Te varying each region, the results obtained are completely different signal light with a speckle pattern.

【0017】したがって、位相分布変調器14により信号光の位相パターンを高速に種々に変化させながら、信号処理部22によりその間の平均の透過率分布を求めることにより、被検体10自身は、例えば図7に示すようにゆっくりとした変化しか示さない場合であっても、ランダムに現れるスペックルパターンの影響を効果的にかつ高速に除去することができる。 [0017] Thus, while the phase pattern of the signal light by the phase distribution modulator 14 is changed variously in a high speed, the signal processing section 22 by finding the transmittance distribution of the average between them, the subject 10 itself, for example, FIG. even if exhibit only slow changes as shown in 7, can be removed effectively and faster the influence of speckle pattern appearing random.

【0018】尚、図2に示す位相分布変調器14は信号光を反射する反射型のものであるが、例えば印加電圧により屈折率が変化する素子を配列し、そこを透過する信号光に位相分布を与えてもよく、本発明にいう位相分布変調器は特定の構成のものに限定されるものではない。 [0018] Incidentally, the phase distribution modulator 14 shown in FIG. 2 is of the reflection type for reflecting the signal light, for example, an element whose refractive index changes aligned by an applied voltage, the phase to the signal light transmitted therethrough distribution may give a phase distribution modulator according to the present invention is not intended to be limited to the particular configuration.
図3は、位相分布変調器を備えることの有効性を示す実験結果を表わした図である。 Figure 3 is a diagram showing the experimental results showing the effectiveness of a phase distribution modulator.

【0019】図3(A)は、厚み1mmのとりのささみ肉に波長1.06μmのNd:YAGレーザ(ビーム径約400μm)を入射して、その透過光を8×8の二次元ヘテロダイン検出器アレイ(各受光素子の大きさは3 [0019] FIG. 3 (A), Nd wavelength 1.06μm to Sasaminiku of possible thickness 1 mm: and incident YAG laser (beam diameter of about 400 [mu] m), two-dimensional heterodyne detector of transmitted light 8 × 8 array (the size of each light receiving element 3
00μm×300μm、アレイ全体の大きさは3mm× 00μm × 300μm, the overall size of the array is 3mm ×
3mm)で検出した結果である。 Is the result detected by the 3mm). また、図3(B)は、 Further, FIG. 3 (B),
同じ実験を厚み7mmのとりのささ身肉について実施した結果である。 Is the result of carried out on chicken breast meat of taking the thickness of 7mm the same experiment.

【0020】これらの結果から、顕著な光散乱が起きる媒質においても入射光軸の近傍で散乱を受けながら伝播した近軸前方散乱光はコヒーレンスをもっており、その結果、光ヘテロダイン検出法で測定した入射ビームの像は、入射ビーム径よりも広がった像となっている。 [0020] From these results, it paraxial forward scattered light propagated while being scattered in the vicinity of the incident optical axis even medium remarkable light scattering to occur has a coherence, resulting incidence measured by optical heterodyne detection method beam image of has a widened image than the incident beam diameter. 以上の実験結果から入射ビームを拡大し、さらにそれを多数の位相差をもつ平面波に分割するという方式を採用し、 Adopts a method of expanding the incident beam from the above experimental results, further divides it into plane wave having a large number of phase difference,
これら平面波の分割領域の広さを適切に設定すれば、各光波の透過光成分どうしが観測面上で干渉し合うことは明白である。 By appropriately setting the size of the divided regions of these plane waves, it is evident that each other transmitted light component of the light wave interfere on the observation surface. 各分割領域どうしの位相差を0〜2πの間でランダムに高速変化させれば、これに追随したスペックル変化からスペックル平均を行なうことが可能である。 If randomly caused to fast changes between 0~2π the phase difference between each other each of the divided regions, it is possible to perform speckle average from speckle changes that follow thereto.

【0021】尚、二次元ヘテロダインアレイを用いた前例として、例えば「K.P.Chan, D.K.Ki [0021] As precedent using a two-dimensional heterodyne array, for example, "K.P.Chan, D.K.Ki
llinger ”Optics Letters” llinger "Optics Letters"
vol. vol. 16, 1219(1991)」はその種の最初の例ともいわれるが、そこでの実験は、各アレイ素子の出力を合成して伝播光路上ではげしい空間コヒーレンス損を生じた光信号の信号対雑音比を向上させようというものであり、本発明とは本質的に異なるものである。 16, 1219 (1991) "is also referred to as the first example of its kind, where experiments, the signal-to-noise ratio of the optical signal resulting synthesized severe spatial coherence loss in the propagation optical path to the output of each array element are those that try to improve, the present invention are essentially different.

【0022】図4は、本発明の光計測装置の第2実施形態の構成図である。 FIG. 4 is a block diagram of a second embodiment of the optical measuring apparatus of the present invention. 図1に示す実施形態の構成要素と同一の構成要素には図1に付した符号を同一の符号を付して示す。 The same components as those of the embodiment shown in FIG. 1 shows the reference numerals affixed to FIG. 1 are denoted by the same reference numerals. レーザ光源11から出射したレーザ光11a Laser beam 11a emitted from the laser light source 11
は、偏光子100で直線偏光にされた後、偏光ビームスプリッタ12により、互いに直交する方向に偏光した信号光11bと参照光11cとに二分される。 Is made into a linearly polarized light by the polarizer 100, the polarizing beam splitter 12, it is divided into a reference light 11c and the signal light 11b polarized in directions perpendicular to each other. 信号光11 Signal light 11
bは、ビームエクスパンダ13および位相分布変調器1 b, the beam expander 13 and the phase distribution modulator 1
4を経た後、偏光プリズム101に入射する。 After a 4, it enters the polarizing prism 101. この偏光プリズム101は、位相分布変調器14側から入射した信号光を透過する向きに配置されている。 The polarizing prism 101 is oriented so as to transmit the signal light incident from the phase distribution modulator 14 side. この偏光プリズム101を透過した信号光は、更にλ/4板102を透過し、被検体配置部15に配置された被検体10を透過し、ミラー103で反射して被検体10を再度透過し、さらにλ/4板102をもう一度透過することにより、往路の信号光と比べその偏光方向が90度回転した状態で偏光プリズム101に再入射する。 Signal light transmitted through the polarizing prism 101, further passes through the lambda / 4 plate 102, transmitted through the subject 10 disposed on the subject placement unit 15, the subject 10 passes again reflected by the mirror 103 further by again passing through the lambda / 4 plate 102, the polarization direction than the outward of the signal light is incident again on the polarizing prism 101 in the state rotated by 90 degrees. この偏光プリズム101に再入射した信号光は往路の信号光と比べ、 Signal light re-incident on the polarizing prism 101 is compared to the forward path of the signal light,
その偏光方向が90度異なっているため、今度はその偏光プリズム101で反射し、ビームスプリッタ104により、偏光方向が同一の参照光11cと強度的に重畳される。 Since its polarization direction is different by 90 degrees in turn is reflected by the polarizing prism 101, a beam splitter 104, the polarization direction is superposed same reference beam 11c and intensity basis.

【0023】一方、偏光ビームスプリッタ12で信号光11bとに二分された参照光11cは、ミラー18で反射し、AOM19で周波数シフトを受け、2枚のレンズ20a,20bからなるビームエクスパンダ20でビーム径が拡大され、ビームスプリッタ104により信号光と強度的に重畳される。 On the other hand, the reference beam 11c which is divided into a signal light 11b by the polarization beam splitter 12 is reflected by the mirror 18, subjected to frequency shift by AOM19, 2 lenses 20a, a beam expander 20 consisting 20b beam diameter is enlarged and superimposed by the beam splitter 104 to the signal light and strength. 上述したように、信号光はλ/ As described above, the signal light is lambda /
4板102を2回透過することによりその偏光方向が9 4 plate 102 its polarization direction by passing through twice 9
0度回転し、これにより参照光と同一の偏光方向を持つ光となる。 It rotated 0 degrees, the thereby light having the same polarization direction and the reference light. したがって、受光器17にはそれら信号光と参照光が干渉した干渉光が入射する。 Therefore, interference light and reference light which signal light interfere is incident on the light receiver 17.

【0024】本実施形態では駆動回路141により駆動された位相分布変調器14により、位相空間分布が種々に高速に変化した信号光が生成され、その位相分布を種々に変化させている間の時間平均的な透過率分布が求められ、スペックルの影響が除去される。 [0024] The phase distribution modulator 14 which is driven by the drive circuit 141 in the present embodiment, the phase space distribution variously signal light and changed to a high speed is generated, the time while changing the phase distribution in various average transmittance distribution is obtained, the influence of the speckle is removed. 本実施形態では信号光が被検体10を二度透過しているため、被検体1 Because the present embodiment the signal light is transmitted through the object 10 twice, the subject 1
0の透過率分布が一層はっきりとした信号強度分布として現れた画像を得ることができる。 Transmittance distribution of 0 can be obtained an image which appears as a more distinct signal intensity distribution.

【0025】 [0025]

【発明の効果】以上説明したように、本発明によれば、 As described in the foregoing, according to the present invention,
統計的にランダムなスペックルパターンを強制的に高速に変化させることができ、スペックルパターンに起因する雑音を有効に、かつ高速に除去することができ、高速の光計測が可能となる。 Statistically it is possible to change forcibly fast random speckle pattern, to enable the noise due to the speckle pattern, and can be removed at high speed, it is possible to high-speed optical measurement.

【図面の簡単な説明】 BRIEF DESCRIPTION OF THE DRAWINGS

【図1】本発明の光計測装置の第1実施形態の構成図である。 1 is a configuration diagram of a first embodiment of an optical measuring apparatus of the present invention.

【図2】図1にブロックで示す位相分布変調器の一構成例を示す図である。 2 is a diagram showing one configuration example of the phase distribution modulator shown in block in Fig.

【図3】位相分布変調器を備えることの有効性を示す実験結果を表わした図である。 3 is a diagram showing the experimental results showing the effectiveness of a phase distribution modulator.

【図4】本発明の光計測装置の第2実施形態の構成図である。 4 is a block diagram of a second embodiment of the optical measuring apparatus of the present invention.

【図5】レーザスペックル現象による信号強度の時間変化を示した図である。 5 is a diagram showing the time variation of the signal intensity due to the laser speckle phenomenon.

【図6】レーザスペックル現象による信号強度の時間変化を示した図である。 6 is a diagram showing the time variation of the signal intensity due to the laser speckle phenomenon.

【図7】レーザスペックル現象による信号強度の時間変化を示した図である。 7 is a diagram showing the time variation of the signal intensity due to the laser speckle phenomenon.

【符号の説明】 DESCRIPTION OF SYMBOLS

10 光散乱被検体 11 レーザ光源 11a レーザ光 11b 信号光 11c 参照光 12 ビームスプリッタ 13 ビームエクスパンダ 14 位相分布変調器 15 被検体配置部 16 ビームスプリッタ 17 受光器 17a,17b,…,17n 受光素子 18 ミラー 19 AOM 20 ビームエクスパンダ 22 信号処理部 23 ディスプレイ 100 偏光子 101 偏光プリズム 102 λ/4板 103 ミラー 141 駆動回路 10 light scattering specimen 11 laser light source 11a laser light 11b the signal light 11c reference light 12 beam splitter 13 the beam expander 14 phase distribution modulator 15 subject placement portion 16 beam splitter 17 optical receiver 17a, 17b, ..., 17n receiving element 18 mirror 19 AOM 20 the beam expander 22 the signal processing unit 23 display 100 polarizer 101 polarizing prism 102 lambda / 4 plate 103 mirror 141 driving circuit

───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl. 7 ,DB名) G01J 9/00 - 9/04 G01N 21/00 - 21/61 G01B 9/00 - 9/10 ────────────────────────────────────────────────── ─── of the front page continued (58) investigated the field (Int.Cl. 7, DB name) G01J 9/00 - 9/04 G01N 21/00 - 21/61 G01B 9/00 - 9/10

Claims (1)

    (57)【特許請求の範囲】 (57) [the claims]
  1. 【請求項1】 コヒーレント光を出射する光源と、 被検体が配置される被検体配置部と、 前記光源から出射されたコヒーレント光を二分して 、前記被検体配置部を経由するビーム径が拡大された信号光と、該被検体配置部を経由する光路とは異なる光路を経由する、ビーム径が拡大された、前記信号光とは相対的 A light source for emitting 1. A coherent light bisects the subject placement portion is disposed object, the coherent light emitted from said light source, said beam diameter passing through the object arrangement unit is larger a signal light, through the different light paths from the light path passing through the analyte placement section, the beam diameter is expanded, relative to the said optical signal
    に周波数が異なる参照光とを生成するとともに、該被検体配置部を経由した後の信号光と、異なる光路を経由した参照光とを互いに重畳することにより該信号光と該参照光とが干渉した干渉光を生成する干渉光学系と、 前記干渉光学系で生成された干渉光のビーム内を複数の Frequency to produce a different reference light with the signal light after passing through the analyte placement unit, the signal light and by superimposing the reference light propagated through different optical paths from each other reference light Metropolitan interference the interference optical system for generating an interference light beam in a plurality of the generated interference light by said interference optical system
    領域に分割したときの各分割領域それぞれを独立に受光 Independently receiving the respective divided areas when the divided region
    する、配列された複数の受光素子を有する受光器と、 前記被検体配置部に達する前の信号光の光路上に配置され、該信号光のビーム内を複数の領域に分割したとき To, a photodetector to have a plurality of light receiving elements arranged, the is disposed on the optical path of the signal light before reaching the subject placement unit, when dividing the inside of the beam of the signal light into a plurality of regions
    の、これら複数の分割領域の位相パターンを時間的に順次変化させる位相分布変調器と、 前記位相分布変調器で前記信号光の位相パターンを順次 Of the phase distribution modulator to temporally sequentially changing the phase pattern of these plurality of divided regions, the phase pattern of the signal light by the phase distribution modulator sequentially
    変化させる間の前記受光器の出力を平均化する平均演算 The average calculation for averaging the output of said photodetector while changing
    部とを備えたことを特徴とする光計測装置。 Optical measuring device is characterized in that a part.
JP01554497A 1997-01-29 1997-01-29 Optical measurement device Expired - Lifetime JP3213250B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP01554497A JP3213250B2 (en) 1997-01-29 1997-01-29 Optical measurement device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP01554497A JP3213250B2 (en) 1997-01-29 1997-01-29 Optical measurement device

Publications (2)

Publication Number Publication Date
JPH10213485A JPH10213485A (en) 1998-08-11
JP3213250B2 true JP3213250B2 (en) 2001-10-02

Family

ID=11891741

Family Applications (1)

Application Number Title Priority Date Filing Date
JP01554497A Expired - Lifetime JP3213250B2 (en) 1997-01-29 1997-01-29 Optical measurement device

Country Status (1)

Country Link
JP (1) JP3213250B2 (en)

Families Citing this family (37)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1434522B1 (en) 2000-10-30 2010-01-13 The General Hospital Corporation Optical systems for tissue analysis
CA2519937C (en) 2003-03-31 2012-11-20 Guillermo J. Tearney Speckle reduction in optical coherence tomography by path length encoded angular compounding
WO2006014392A1 (en) 2004-07-02 2006-02-09 The General Hospital Corporation Endoscopic imaging probe comprising dual clad fibre
EP2272420B1 (en) 2004-08-24 2013-06-19 The General Hospital Corporation Apparatus for imaging of vessel segments
WO2006058346A1 (en) 2004-11-29 2006-06-01 The General Hospital Corporation Arrangements, devices, endoscopes, catheters and methods for performing optical imaging by simultaneously illuminating and detecting multiple points on a sample
ES2337497T3 (en) 2005-04-28 2010-04-26 The General Hospital Corporation Evaluation of characteristics of the image of an anatomical structure images of optical coherence tomography.
EP1889037A2 (en) 2005-06-01 2008-02-20 The General Hospital Corporation Apparatus, method and system for performing phase-resolved optical frequency domain imaging
JP4613110B2 (en) * 2005-07-20 2011-01-12 アンリツ株式会社 Light interference type phase detector
CN101238347B (en) 2005-08-09 2011-05-25 通用医疗公司 Apparatus, methods and storage medium for performing polarization-based quadrature demodulation in optical coherence tomography
KR20080066705A (en) 2005-09-29 2008-07-16 더 제너럴 하스피탈 코포레이션 Method and apparatus for method for viewing and analyzing of one or more biological smaples with progressively increasing resolutions
WO2007084995A2 (en) 2006-01-19 2007-07-26 The General Hospital Corporation Methods and systems for optical imaging of epithelial luminal organs by beam scanning thereof
US8145018B2 (en) 2006-01-19 2012-03-27 The General Hospital Corporation Apparatus for obtaining information for a structure using spectrally-encoded endoscopy techniques and methods for producing one or more optical arrangements
CN101370426A (en) * 2006-01-20 2009-02-18 通用医疗公司 Systems, arrangement and process for providing speckle reductions using a wave front modulation for optical coherence tomography
EP2659852A3 (en) 2006-02-01 2014-01-15 The General Hospital Corporation Apparatus for applying a plurality of electro-magnetic radiations to a sample
JP2009527770A (en) 2006-02-24 2009-07-30 ザ ジェネラル ホスピタル コーポレイション Angle-resolved Fourier domain optical coherence tomography performing method and system
EP2015669A2 (en) 2006-05-10 2009-01-21 The General Hospital Corporation Processes, arrangements and systems for providing frequency domain imaging of a sample
WO2008049118A2 (en) 2006-10-19 2008-04-24 The General Hospital Corporation Apparatus and method for obtaining and providing imaging information associated with at least one portion of a sample and effecting such portion(s)
EP3330696A1 (en) 2008-12-10 2018-06-06 The General Hospital Corporation Systems, apparatus and methods for extending imaging depth range of optical coherence tomography through optical sub-sampling
WO2010090837A2 (en) 2009-01-20 2010-08-12 The General Hospital Corporation Endoscopic biopsy apparatus, system and method
US9178330B2 (en) 2009-02-04 2015-11-03 The General Hospital Corporation Apparatus and method for utilization of a high-speed optical wavelength tuning source
EP2542154A4 (en) 2010-03-05 2014-05-21 Gen Hospital Corp Systems, methods and computer-accessible medium which provide microscopic images of at least one anatomical structure at a particular resolution
US9069130B2 (en) 2010-05-03 2015-06-30 The General Hospital Corporation Apparatus, method and system for generating optical radiation from biological gain media
JP5778762B2 (en) 2010-05-25 2015-09-16 ザ ジェネラル ホスピタル コーポレイション Apparatus and method for spectral analysis of optical coherence tomography images
WO2011149972A2 (en) 2010-05-25 2011-12-01 The General Hospital Corporation Systems, devices, methods, apparatus and computer-accessible media for providing optical imaging of structures and compositions
EP2575591A4 (en) 2010-06-03 2017-09-13 The General Hospital Corporation Apparatus and method for devices for imaging structures in or at one or more luminal organs
US9510758B2 (en) 2010-10-27 2016-12-06 The General Hospital Corporation Apparatus, systems and methods for measuring blood pressure within at least one vessel
JP2014523536A (en) 2011-07-19 2014-09-11 ザ ジェネラル ホスピタル コーポレイション System for providing a polarization mode dispersion compensation in an optical coherence tomography method, apparatus and computer-accessible medium
JP2015502562A (en) 2011-10-18 2015-01-22 ザ ジェネラル ホスピタル コーポレイション Apparatus and method for generating and / or providing a recirculation optical delay
WO2013148306A1 (en) 2012-03-30 2013-10-03 The General Hospital Corporation Imaging system, method and distal attachment for multidirectional field of view endoscopy
WO2014031748A1 (en) 2012-08-22 2014-02-27 The General Hospital Corporation System, method, and computer-accessible medium for fabrication minature endoscope using soft lithography
JP2016505345A (en) 2013-01-28 2016-02-25 ザ ジェネラル ホスピタル コーポレイション Apparatus and method for providing a diffusion spectroscopy to be superposed on the optical frequency domain imaging
US9784681B2 (en) 2013-05-13 2017-10-10 The General Hospital Corporation System and method for efficient detection of the phase and amplitude of a periodic modulation associated with self-interfering fluorescence
EP3021735A4 (en) 2013-07-19 2017-04-19 The General Hospital Corporation Determining eye motion by imaging retina. with feedback
EP3025173A4 (en) 2013-07-26 2017-03-22 The General Hospital Corporation System, apparatus and method utilizing optical dispersion for fourier-domain optical coherence tomography
WO2015105870A1 (en) 2014-01-08 2015-07-16 The General Hospital Corporation Method and apparatus for microscopic imaging
US10228556B2 (en) 2014-04-04 2019-03-12 The General Hospital Corporation Apparatus and method for controlling propagation and/or transmission of electromagnetic radiation in flexible waveguide(s)
CN105445492A (en) * 2015-12-14 2016-03-30 华中科技大学 Scattering medium-penetrating laser speckle flow speed detection method and device thereof

Also Published As

Publication number Publication date
JPH10213485A (en) 1998-08-11

Similar Documents

Publication Publication Date Title
Maznev et al. How to make femtosecond pulses overlap
US6233470B1 (en) Absorption information measuring method and apparatus of scattering medium
KR940009241B1 (en) Distance measuring method and apparatus therefor
US5892583A (en) High speed inspection of a sample using superbroad radiation coherent interferometer
US8204300B2 (en) Image forming method and optical coherence tomograph apparatus using optical coherence tomography
JP4286667B2 (en) Low coherence interference device for the object optical scanning
Lowenthal et al. Speckle removal by a slowly moving diffuser associated with a motionless diffuser
EP1443856B1 (en) Blood flow velocity measurement
US5555087A (en) Method and apparatus for employing a light source and heterodyne interferometer for obtaining information representing the microstructure of a medium at various depths therein
KR101387454B1 (en) Apparatus, methods and storage medium for performing polarization-based quadrature demodulation in optical coherence tomography
US20150077755A1 (en) Method and apparatus for performing optical imaging using frequency-domain interferometry
US6014214A (en) High speed inspection of a sample using coherence processing of scattered superbroad radiation
EP1257869B1 (en) Method and apparatus for reducing laser speckle using polarization averaging
JP2916500B2 (en) Imaging method and system for fluoroscopy using photon frequency marking
US20030090674A1 (en) System and method for performing selected optical measurements
US5822047A (en) Modulator LIDAR system
US4115753A (en) Fiber optic acoustic array
JP4045140B2 (en) Method of measuring the sample inside the polarization information by polarization sensitive optical spectral interference coherence tomography apparatus and the apparatus
JP4409384B2 (en) The optical image measurement device and an optical image measuring method
US4468093A (en) Hybrid space/time integrating optical ambiguity processor
JP4381847B2 (en) The optical image measurement device
US20090015842A1 (en) Phase Sensitive Fourier Domain Optical Coherence Tomography
Abbott et al. Acoustic speckle: Theory and experimental analysis
US7161664B2 (en) Apparatus and method for optical determination of intermediate distances
EP1002497A2 (en) Blood vessel imaging system

Legal Events

Date Code Title Description
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20010710