JPH04310847A - Device and method for detecting phase of interference fringe - Google Patents
Device and method for detecting phase of interference fringeInfo
- Publication number
- JPH04310847A JPH04310847A JP7779891A JP7779891A JPH04310847A JP H04310847 A JPH04310847 A JP H04310847A JP 7779891 A JP7779891 A JP 7779891A JP 7779891 A JP7779891 A JP 7779891A JP H04310847 A JPH04310847 A JP H04310847A
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- 238000000034 method Methods 0.000 title abstract description 24
- 238000001514 detection method Methods 0.000 claims abstract description 8
- 230000003287 optical effect Effects 0.000 claims description 10
- 230000001360 synchronised effect Effects 0.000 claims 1
- 238000005259 measurement Methods 0.000 abstract description 24
- 230000004907 flux Effects 0.000 abstract 1
- 239000011521 glass Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000003384 imaging method Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
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- Investigating Or Analysing Materials By Optical Means (AREA)
- Instruments For Measurement Of Length By Optical Means (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は、試料の屈折率分布や面
形状などを光の干渉縞として検出する際の干渉縞の位相
検出装置及び位相検出方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for detecting the phase of interference fringes when detecting the refractive index distribution, surface shape, etc. of a sample as interference fringes of light.
【０００２】0002
【従来の技術】試料の屈折率分布や面形状を測定する装
置としては、マッハツェンダー干渉計やトワイマングリ
ーン干渉計を用いたものがある。これらの測定装置では
、屈折率分布や面形状を光の波面に換算し、その波面を
別の参照波面と干渉させ、それらの干渉縞として波面の
情報を得て屈折率分布や面形状を測定するようになって
いる。2. Description of the Related Art As an apparatus for measuring the refractive index distribution and surface shape of a sample, there are apparatuses using a Mach-Zehnder interferometer or a Twyman Green interferometer. These measurement devices convert the refractive index distribution and surface shape into a light wavefront, interfere with another reference wavefront, obtain information about the wavefront as interference fringes, and measure the refractive index distribution and surface shape. It is supposed to be done.
【０００３】例えば、ガラスの屈折率分布を測定する装
置としては、図４に示したようなマッハツェンダー干渉
計を応用したものが知られている。図４において、１は
レーザー光源、２はビームエキスパンダ、３はハーフミ
ラー、４，５はミラー、６はハーフミラー、７は結像レ
ンズ、８はＣＣＤイメージセンサーである。レーザー光
源１からの光束はビームエキスパンダ２により適当な太
さの光束になり、ハーフミラー３により２つに分割され
、各々ミラー４，５によりそれぞれ反射されてハーフミ
ラー６において１つに合成される。９は分割された光束
の一方の光路中に配置された測定対象物である試料であ
って、ここでは平行平板となるように研磨された屈折率
分布を持つガラス板である。この試料９の存在により一
方の光束の波面が変形するので、ハーフミラー６により
合成された２光束が干渉して干渉縞が形成される。そし
て、干渉縞が結像レンズ７によりＣＣＤイメージセンサ
ー８上に結像せしめられるので、干渉縞の形状を読み取
ることができる。For example, as a device for measuring the refractive index distribution of glass, a device using a Mach-Zehnder interferometer as shown in FIG. 4 is known. In FIG. 4, 1 is a laser light source, 2 is a beam expander, 3 is a half mirror, 4 and 5 are mirrors, 6 is a half mirror, 7 is an imaging lens, and 8 is a CCD image sensor. A beam of light from a laser light source 1 is made into a beam of appropriate thickness by a beam expander 2, split into two by a half mirror 3, each reflected by mirrors 4 and 5, and combined into one beam by a half mirror 6. Ru. Reference numeral 9 denotes a sample to be measured, which is placed in one of the optical paths of the divided light beams, and here is a glass plate having a refractive index distribution that has been polished to form a parallel plate. The presence of the sample 9 deforms the wavefront of one of the light beams, so the two light beams combined by the half mirror 6 interfere and form interference fringes. Since the interference fringes are imaged onto the CCD image sensor 8 by the imaging lens 7, the shape of the interference fringes can be read.
【０００４】試料９の内部の屈折率差をΔｎ、試料９の
厚さをｄ、測定に用いられる光の波長をλとすると、試
料９の存在に起因する干渉縞の位相変化Δφは次の式で
与えられる。
Δφ＝２π・（Δｎ・ｄ）／λIf the refractive index difference inside the sample 9 is Δn, the thickness of the sample 9 is d, and the wavelength of the light used for measurement is λ, then the phase change Δφ of the interference fringe due to the presence of the sample 9 is as follows. It is given by Eq. Δφ=2π・(Δn・d)/λ
【０００５】ここで、屈折率差Δｎを精度良く測定する
ためには、位相変化Δφと厚みｄを非常に精度良く測る
必要があるが、それらの測定は非常に難しい。この時、
厚みｄを大きくしてやるとΔφやｄの測定精度は低くて
済むが、Δφが大きくなって得られる縞が非常に細かい
ものとなる。例えば、試料全体で数百本の縞がでること
がある。この場合、縞全体をＣＣＤイメージセンサー８
で検出することはＣＣＤイメージセンサー８の画素の大
きさがあまり小さくないことから非常に難しくなる。[0005] In order to accurately measure the refractive index difference Δn, it is necessary to measure the phase change Δφ and the thickness d with extremely high accuracy, but these measurements are extremely difficult. At this time,
If the thickness d is increased, the measurement precision of Δφ and d can be lowered, but Δφ increases and the resulting stripes become very fine. For example, hundreds of stripes may appear across the sample. In this case, the entire stripe is captured by the CCD image sensor 8.
Detection is extremely difficult because the size of the pixels of the CCD image sensor 8 is not very small.
【０００６】[0006]
【発明が解決しようとする課題】そこで、ＣＣＤイメー
ジセンサー８で試料全体のデータを同時に検出する代わ
りに、試料９のある一点だけを測定しながら試料９を走
査する方法が考えられる。このように試料９を走査しな
がら波面を測定する方法としては、特開昭６３−１７９
２２４号公報に記載のものがある。この方法は、干渉縞
の強度を強くできる上、装置全体を小型化できるという
特徴を持っている。又、干渉縞の位相検出にヘテロダイ
ン法を用いており、実時間で位相の測定ができるという
利点もある。しかし、ゼーマンレーザーやブラッグセル
等の特殊な２波長光源が必要となり、構成が複雑になる
という問題がある。SUMMARY OF THE INVENTION Therefore, instead of simultaneously detecting the data of the entire sample using the CCD image sensor 8, a method may be considered in which the sample 9 is scanned while measuring only one point on the sample 9. A method of measuring the wavefront while scanning the sample 9 in this way is disclosed in Japanese Patent Application Laid-Open No. 63-179.
There is one described in Publication No. 224. This method has the characteristics that the intensity of the interference fringes can be increased and that the entire device can be made smaller. Furthermore, the heterodyne method is used to detect the phase of interference fringes, which has the advantage of being able to measure the phase in real time. However, there is a problem that a special two-wavelength light source such as a Zeeman laser or a Bragg cell is required, making the configuration complicated.
【０００７】又、別の方法としてフリンジスキャン法を
用いることも考えられる。フリンジスキャン法は、例え
ば「光学」第１３巻，第１号，５５頁以下に解説されて
いるが、おおよそ以下のようなものである。一般に、こ
の種の干渉計により形成される干渉縞の強度分布ｇは、
ｇ＝ａ＋ｂｃｏｓφ
と表すことができる。ここで、ａ，ｂは干渉縞のムラや
コントラストに相当する定数、φは位相情報である。[0007] It is also conceivable to use a fringe scan method as another method. The fringe scanning method is explained, for example, in "Optics" Vol. 13, No. 1, page 55 et seq., and is roughly as follows. Generally, the intensity distribution g of interference fringes formed by this type of interferometer is
It can be expressed as g=a+bcosφ. Here, a and b are constants corresponding to unevenness and contrast of interference fringes, and φ is phase information.
【０００８】この干渉縞から位相情報φ（ｘ，ｙ）を読
み取るにあたり、干渉縞の１周期をＭ（整数）分割する
と、そのｍ番目の信号は、
ｇ（ｍ）＝ａ＋ｂｃｏｓ（２πｍ／Ｍ＋φ）
（ｍ＝０，１，・・・・，Ｍ−１）
となる。これは、参照光と測定光（試料９を通過した光
）との間に２πｍ／Ｍのずれを与えて干渉縞の強度を測
定することに相当する。この信号ｇ（ｍ）の基本周波数
スペクトルＧは、[0008] When reading phase information φ(x, y) from this interference fringe, if one period of the interference fringe is divided into M (integer), the mth signal is g(m)=a+bcos(2πm/M+φ)
(m=0,1,...,M-1)
becomes. This corresponds to measuring the intensity of interference fringes by giving a deviation of 2πm/M between the reference light and the measurement light (light that has passed through the sample 9). The fundamental frequency spectrum G of this signal g(m) is
【０００９】[0009]
【数１】[Math 1]
【００１０】となる。ここで、ｊは虚数単位である。こ
のＧの実部Ｒｅ（Ｇ）と虚部Ｉｍ（Ｇ）を用いて位相φ
が以下のように求まる。
φ＝ｔａｎ−１（Ｉｍ（Ｇ）／Ｒｅ（Ｇ））[0010] Here, j is an imaginary unit. Using the real part Re(G) and imaginary part Im(G) of this G, the phase φ
is calculated as follows. φ=tan-1(Im(G)/Re(G))
【００１１
】このように、フリンジスキャン法では、１点の位相の
値を求めるのにＭ回の測定が必要であるので、１点の測
定時間が長くなってしまうという問題がある。この方法
は、ＣＣＤイメージセンサー８等を用いて試料全体のデ
ータを測定する場合にはほとんど問題にならないが、試
料９を走査して１点１点の測定を繰り返し行う場合には
、１点毎にＭ回の測定を繰り返すことになり、全体とし
て非常に長い時間がかかることになってしまう。0011
] In this manner, the fringe scan method requires M measurements to obtain the phase value of one point, which poses a problem in that the measurement time for one point becomes long. This method poses almost no problem when measuring data on the entire sample using a CCD image sensor 8, etc., but when scanning the sample 9 and repeatedly measuring point by point, Therefore, the measurement is repeated M times, and the entire process takes a very long time.
【００１２】本発明は、上記問題点に鑑み、試料を走査
しながら干渉縞を計測してその試料内部の屈折率分布や
面形状を測定する際に、簡単な構成で短時間に位相情報
を得ることができるようにするための、干渉縞の位相検
出装置及び方法を提供することを目的としている。In view of the above-mentioned problems, the present invention has a simple structure and can obtain phase information in a short time when measuring interference fringes while scanning a sample to measure the refractive index distribution and surface shape inside the sample. It is an object of the present invention to provide an apparatus and method for detecting the phase of interference fringes.
【００１３】[0013]
【課題を解決するための手段】本発明による干渉縞の測
定装置は、光源と、該光源から発する光を２光束に分割
する光束分割手段と、分割された前記２光束を合成する
光束合成手段と、前記２光束の一方の光路中に配置され
た測定対象物を走査する走査手段と、該走査手段の走査
方向に沿って配列された複数の受光素子を備えていて前
記合成光束が形成する干渉縞を検出する検出手段と、前
記走査手段の走査に同期して前記２光束の間に位相差を
付与する位相差付与手段とを備えていることを特徴とし
ている。[Means for Solving the Problems] An apparatus for measuring interference fringes according to the present invention includes a light source, a beam splitting means for dividing the light emitted from the light source into two beams, and a beam combining means for combining the two divided beams. and a scanning means for scanning an object to be measured disposed in the optical path of one of the two light beams, and a plurality of light receiving elements arranged along the scanning direction of the scanning means, so that the combined light beam is formed. It is characterized by comprising a detection means for detecting interference fringes, and a phase difference applying means for applying a phase difference between the two light beams in synchronization with scanning by the scanning means.
【００１４】又、本発明による干渉縞の測定方法は、光
源から発する光を一旦２光束に分割した後該２光束を合
成し、前記分割された２光束の一方の光路中に配置され
た測定対象物を走査し、該走査に同期して前記２光束の
間に位相差を付与し、複数の受光素子により前記合成光
束が形成する干渉縞を検出するようにしたことを特徴と
している。[0014] Furthermore, in the method for measuring interference fringes according to the present invention, the light emitted from the light source is once divided into two beams, and then the two beams are combined, and a measurement device placed in the optical path of one of the two divided beams is used. The present invention is characterized in that a target object is scanned, a phase difference is provided between the two light beams in synchronization with the scanning, and interference fringes formed by the combined light beam are detected by a plurality of light receiving elements.
【００１５】[0015]
【作用】図１は本発明による干渉縞の位相測定装置の概
略図であって、上記従来例と同一の部材には同一符号を
付してそれらの説明は省略する。１０はその反射面と垂
直な方向に移動可能なミラー、１１は分割された光束の
一方の光路（測定光路）中に光軸に対して垂直な方向に
走査可能に配置された測定対象物である試料、１２は試
料１１の走査方向と平行に配列されたフォトダイオード
等の受光素子ＰＤ１，ＰＤ２，ＰＤ３，ＰＤ４を備えた
検出装置である。ここで、結像レンズ７の作用により、
試料１１のＡ１，Ａ２，Ａ３，Ａ４の位置にある各点の
像がそれぞれ丁度受光素子ＰＤ１，ＰＤ２，ＰＤ３，Ｐ
Ｄ４の上に結像されるようになっている。又、位置Ａ１
，Ａ２，Ａ３，Ａ４の各間隔は、ｌである。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram of a phase measuring apparatus for interference fringes according to the present invention, in which the same members as those in the conventional example described above are given the same reference numerals and their explanations will be omitted. 10 is a mirror movable in a direction perpendicular to its reflecting surface; 11 is a measurement object disposed in one optical path (measurement optical path) of the divided light beam so as to be scannable in a direction perpendicular to the optical axis. A certain sample 12 is a detection device equipped with light receiving elements PD1, PD2, PD3, and PD4 such as photodiodes arranged parallel to the scanning direction of the sample 11. Here, due to the action of the imaging lens 7,
The images of the points at positions A1, A2, A3, and A4 of the sample 11 are exactly the same as those of the photodetectors PD1, PD2, PD3, and P, respectively.
The image is formed on D4. Also, position A1
, A2, A3, and A4 are each spaced by l.
【００１６】本発明装置及び方法の要点は、試料１１を
走査する（動かす）度毎に参照光の位相を変化させると
ころにある。測定すべきある１点Ｘｉ がまずＡ１の位
置にあったとする。この時の点Ｘｉ を通過した光の強
度は受光素子ＰＤ１で検出される。次に試料１１をｌだ
け走査する（動かす）と測定点Ｘｉ はＡ２の位置に移
動し、その時の点Ｘｉ を通過した光の強度は受光素子
ＰＤ２で検出される。この場合、試料１１をｌだけ走査
すると同時にミラー１０を動かして参照光の位相をπ／
２だけずらしておく。更に、参照光の位相を順次π／２
ずつずらしながら、測定点Ｘｉ をＡ３，Ａ４と移動さ
せ、その時の点Ｘｉ を通過した光の強度を受光素子Ｐ
Ｄ３，ＰＤ４で検出する。以上の場合の測定点Ｘｉ の
位置とそれを通過した光の強度を検出する受光素子と参
照光の位相との関係を次の表１に示す。The key point of the apparatus and method of the present invention is to change the phase of the reference light each time the sample 11 is scanned (moved). Assume that a certain point Xi to be measured is first located at position A1. The intensity of the light passing through the point Xi at this time is detected by the light receiving element PD1. Next, when the sample 11 is scanned (moved) by l, the measuring point Xi moves to the position A2, and the intensity of the light passing through the point Xi at that time is detected by the light receiving element PD2. In this case, the sample 11 is scanned by l and at the same time the mirror 10 is moved to adjust the phase of the reference light by π/
Shift it by 2. Furthermore, the phase of the reference light is sequentially changed to π/2.
The measurement point Xi is moved to A3 and A4, and the intensity of the light passing through the point Xi at that time is measured by the light receiving element P.
Detected by D3 and PD4. Table 1 below shows the relationship between the position of the measurement point Xi, the light receiving element that detects the intensity of the light passing through it, and the phase of the reference light in the above case.
【００１７】[0017]
【表１】[Table 1]
【００１８】このようにして、ある測定すべき点Ｘｉ
は、位置Ａ１，Ａ２，Ａ３，Ａ４を通る度毎に点Ｘｉ
を通過した光の位相がπ／２ずつ変化して測定できるこ
とになる。従って、受光素子ＰＤ１，ＰＤ２，ＰＤ３，
ＰＤ４からの強度信号により前に述べたフリンジスキャ
ン法と同じ原理で測定すべき点の位相φが求まることに
なる。In this way, a certain point Xi to be measured
points Xi every time it passes through positions A1, A2, A3, and A4.
This means that the phase of the light that has passed can be measured by changing by π/2. Therefore, the light receiving elements PD1, PD2, PD3,
Using the intensity signal from the PD 4, the phase φ of the point to be measured can be determined using the same principle as the fringe scan method described above.
【００１９】これまで、ある１つの測定点Ｘｉ につい
てのみ考えたが、実際には点Ｘｉ の前後にある測定点
・・・・，Ｘｉ＋１ ，Ｘｉ−１ ，・・・・もそれが
位置Ａ１，Ａ２，Ａ３，Ａ４にくれば、同時に測定され
る。即ち、試料１１をｌだけ走査する毎に位置Ａ１，Ａ
２，Ａ３，Ａ４を通過した光の位相の測定が１度にでき
ることになる。Up to now, we have considered only one measurement point Xi, but in reality, the measurement points before and after point Xi..., Xi+1, Xi-1,... are also at position A1, When A2, A3, and A4 are reached, they are measured at the same time. That is, every time the sample 11 is scanned by l, the positions A1 and A
2, A3, and A4 can be measured at one time.
【００２０】参考のために、測定点Ｘｉ＋１ の位置と
それを通過した光の強度を検出する受光素子と参照光の
位相との関係を次の表２に示す。For reference, Table 2 below shows the relationship between the position of the measurement point Xi+1, the light receiving element that detects the intensity of the light that has passed through it, and the phase of the reference light.
【００２１】[0021]
【表２】[Table 2]
【００２２】この場合、受光素子ＰＤ１，ＰＤ２，ＰＤ
３，ＰＤ４で得られた信号から位相φを求める場合、参
照光の位相が測定点Ｘｉ の場合と違うので、その分を
考慮してやる必要がある。In this case, the light receiving elements PD1, PD2, PD
3. When determining the phase φ from the signal obtained by the PD 4, the phase of the reference light is different from that at the measurement point Xi, so it is necessary to take this into consideration.
【００２３】以上のように、本発明による位相測定装置
及び方法を用いると、試料１１を１回走査する度に４点
を通過した光の位相の測定が１度にできることになるの
で、フリンジスキャン法を用いて各点毎に位相を測定す
る場合に比べて大幅時間短縮が可能となる。又、特殊な
２波長光源を必要としないので、ヘテロダイン法に比べ
て構成が簡単になる。As described above, by using the phase measuring device and method according to the present invention, the phase of the light that has passed through four points can be measured at once each time the sample 11 is scanned once, so the fringe scanning Compared to the case where the phase is measured at each point using the method, it is possible to significantly shorten the time. Furthermore, since a special two-wavelength light source is not required, the configuration is simpler than that of the heterodyne method.
【００２４】[0024]
【実施例】以下、図示した実施例に基づき本発明を詳細
に説明する。図２は本発明による位相測定装置の実施例
１を示しており、これは平行平板状に研磨された試料の
屈折率分布を測定する装置である。この装置は、マッハ
ツェンダー干渉計を用いたものであって、参照光の位相
を変化させるために、ミラー１０をピエゾ素子１３を用
いて反射面と垂直な方向に移動せしめるようになってい
る。又、試料１１は、光軸と垂直な方向に移動可能なス
テージ１４上に配置されている。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below based on the illustrated embodiments. FIG. 2 shows a first embodiment of a phase measuring device according to the present invention, which is a device for measuring the refractive index distribution of a sample polished into a parallel plate shape. This device uses a Mach-Zehnder interferometer, and in order to change the phase of the reference light, the mirror 10 is moved in a direction perpendicular to the reflecting surface using a piezo element 13. Further, the sample 11 is placed on a stage 14 that is movable in a direction perpendicular to the optical axis.
【００２５】本実施は上述の如く構成されているから、
ステージ１４により試料１１を走査するのに同期してピ
エゾ素子１３によりミラー１０を移動させることにより
測定光に対する参照光の位相差を段階的に変化させ、検
出装置１２の受光素子ＰＤ１，ＰＤ２，ＰＤ３，ＰＤ４
により干渉縞を検出すれば、上述の原理により試料１１
を１回走査する度に４点を通過した光の位相の測定が１
度にできることになるので、フリンジスキャン法を用い
て各点毎に位相を測定する場合に比べて大幅時間短縮が
可能となる。又、特殊な２波長光源を必要としないので
、ヘテロダイン法に比べて構成が簡単になる。[0025] Since this implementation is configured as described above,
By moving the mirror 10 using the piezo element 13 in synchronization with the scanning of the sample 11 by the stage 14, the phase difference of the reference light with respect to the measurement light is changed stepwise, and the light receiving elements PD1, PD2, PD3 of the detection device 12 ,PD4
If interference fringes are detected by
The phase of the light that passed through the four points is measured once every time the
Since it can be done at once, it is possible to significantly reduce the time compared to the case where the phase is measured at each point using the fringe scan method. Furthermore, since a special two-wavelength light source is not required, the configuration is simpler than that of the heterodyne method.
【００２６】図３は実施例２を示している。これは実施
例１とほぼ同じ構成の屈折率分布測定装置であるが、実
施例１と異なり、本実施例では測定光の光路中にクサビ
角度を持ったガラス板１５を配置しており、該ガラス板
１５の光の通る位置によって信号光の位相変化の大きさ
が変化するようになっている。従って、試料１１を走査
すると、各測定点の位置が変化し、その結果各測定点を
通過した光と参照光との位相差が自動的に変化すること
になる。尚、位相変化量は、例えば４回測定の場合は、
試料１１の１回の走査（１ｌの移動）につきπ／２にな
るようにクサビ角度とガラスの屈折率を選んでおく必要
がある。FIG. 3 shows a second embodiment. This is a refractive index distribution measuring device having almost the same configuration as Example 1, but unlike Example 1, in this example, a glass plate 15 with a wedge angle is arranged in the optical path of the measurement light. The magnitude of the phase change of the signal light changes depending on the position of the glass plate 15 through which the light passes. Therefore, when the sample 11 is scanned, the position of each measurement point changes, and as a result, the phase difference between the light passing through each measurement point and the reference light changes automatically. In addition, the amount of phase change is, for example, in the case of 4 measurements,
It is necessary to select the wedge angle and the refractive index of the glass so that each scan (1 liter movement) of the sample 11 yields π/2.
【００２７】本実施例では、ピエゾ素子を用いずにクサ
ビ角度を持ったガラス板を用いているので、実施例１よ
りも簡単な構成で装置を構成することができる。In this embodiment, since a glass plate with a wedge angle is used instead of a piezo element, the device can be constructed with a simpler structure than in the first embodiment.
【００２８】上記実施例１及び２はいずれも屈折率分布
を測定する装置であるが、勿論本発明は面形状を測定す
る装置にも応用することができる。又、マッハツェンダ
ー干渉計以外の干渉計にも適用することができる。Both of the above embodiments 1 and 2 are devices for measuring refractive index distribution, but of course the present invention can also be applied to devices for measuring surface shape. Moreover, it can be applied to interferometers other than Mach-Zehnder interferometers.
【００２９】[0029]
【発明の効果】上述の如く、本発明による干渉縞の位相
測定装置及び方法は、試料を走査しながら屈折率分布や
面形状を測定する装置及び方法において、構成が簡単で
測定時間も短くて済むという実用上重要な利点を有して
いる。Effects of the Invention As described above, the interference fringe phase measuring device and method according to the present invention has a simple configuration and a short measurement time in the device and method for measuring refractive index distribution and surface shape while scanning a sample. It has the important practical advantage of being easy to use.
【図１】本発明による干渉縞の位相測定装置の構成を示
す概略図である。FIG. 1 is a schematic diagram showing the configuration of an interference fringe phase measuring device according to the present invention.
【図２】実施例１の構成を示す概略図である。FIG. 2 is a schematic diagram showing the configuration of Example 1.
【図３】実施例２の構成を示す概略図である。FIG. 3 is a schematic diagram showing the configuration of Example 2.
【図４】従来例の構成を示す概略図である。FIG. 4 is a schematic diagram showing the configuration of a conventional example.
１ レーザー光源
２ ビームエキスパンダ３，６
ハーフミラー
５，１０ ミラー
７ 結像レンズ
１１ 試料
１２ 検出装置
１３ ピエゾ素子
１４ ステージ1 Laser light source 2 Beam expander 3, 6
Half mirrors 5, 10 Mirror 7 Imaging lens 11 Sample 12 Detection device 13 Piezo element 14 Stage
Claims (2)
に分割する光束分割手段と、分割された前記２光束を合
成する光束合成手段と、前記２光束の一方の光路中に配
置された測定対象物を走査する走査手段と、該走査手段
の走査方向に沿って配列された複数の受光素子を備えて
いて前記合成光束が形成する干渉縞を検出する検出手段
と、前記走査手段の走査に同期して前記２光束の間に位
相差を付与する位相差付与手段とを備えた、干渉縞の位
相検出装置。1. A light source, a beam splitting means for dividing the light emitted from the light source into two beams, a beam combining means for combining the two divided beams, and a light beam disposed in the optical path of one of the two beams. a scanning means for scanning an object to be measured; a detection means for detecting interference fringes formed by the combined light beam and comprising a plurality of light receiving elements arranged along the scanning direction of the scanning means; and scanning of the scanning means. and a phase difference imparting means for imparting a phase difference between the two light beams in synchronization with the interference fringe phase detection device.
した後該２光束を合成し、前記分割された２光束の一方
の光路中に配置された測定対象物を走査し、該走査に同
期して前記２光束の間に位相差を付与し、複数の受光素
子により前記合成光束が形成する干渉縞を検出するよう
にした、干渉縞の位相検出方法。2. Once the light emitted from the light source is divided into two beams, the two beams are combined, and an object to be measured placed in one of the optical paths of the two divided beams is scanned, and synchronized with the scanning. a phase difference between the two light beams, and a plurality of light receiving elements detect interference fringes formed by the combined light beam.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7779891A JPH04310847A (en) | 1991-04-10 | 1991-04-10 | Device and method for detecting phase of interference fringe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7779891A JPH04310847A (en) | 1991-04-10 | 1991-04-10 | Device and method for detecting phase of interference fringe |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04310847A true JPH04310847A (en) | 1992-11-02 |
Family
ID=13644023
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7779891A Withdrawn JPH04310847A (en) | 1991-04-10 | 1991-04-10 | Device and method for detecting phase of interference fringe |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04310847A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998053733A1 (en) * | 1997-05-26 | 1998-12-03 | Hitachi, Ltd. | Inspection apparatus using optical interferometer |
| NL1021457C2 (en) * | 2002-09-13 | 2004-03-16 | Tno | Method for measuring contour variations. |
-
1991
- 1991-04-10 JP JP7779891A patent/JPH04310847A/en not_active Withdrawn
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998053733A1 (en) * | 1997-05-26 | 1998-12-03 | Hitachi, Ltd. | Inspection apparatus using optical interferometer |
| US6381015B1 (en) | 1997-05-26 | 2002-04-30 | Hitachi, Ltd. | Inspection apparatus using optical interferometer |
| NL1021457C2 (en) * | 2002-09-13 | 2004-03-16 | Tno | Method for measuring contour variations. |
| WO2004025216A1 (en) * | 2002-09-13 | 2004-03-25 | Nederlandse Organisatie Voor Toegepast- Natuurwetenschappelijk Onderzoek Tno | Method for measuring contour variations |
| US7471398B2 (en) | 2002-09-13 | 2008-12-30 | Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno | Method for measuring contour variations |
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Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 19980711 |