JP2002202104A - Face shape measuring device and optical member measured thereby - Google Patents
Face shape measuring device and optical member measured therebyInfo
- Publication number
- JP2002202104A JP2002202104A JP2000398968A JP2000398968A JP2002202104A JP 2002202104 A JP2002202104 A JP 2002202104A JP 2000398968 A JP2000398968 A JP 2000398968A JP 2000398968 A JP2000398968 A JP 2000398968A JP 2002202104 A JP2002202104 A JP 2002202104A
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- Prior art keywords
- shape measuring
- surface shape
- light
- measuring device
- light beam
- Prior art date
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- Instruments For Measurement Of Length By Optical Means (AREA)
- Length Measuring Devices By Optical Means (AREA)
- Testing Of Optical Devices Or Fibers (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、レンズ、ミラーな
どの光学素子の面形状を、高精度に測定するための面形
状測定装置及び該装置により測定された光学部材に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface shape measuring device for measuring the surface shape of an optical element such as a lens or a mirror with high accuracy, and an optical member measured by the device.
【０００２】[0002]
【従来の技術】近年、高精度な光学機器の需要に伴い、
その機器を構成するレンズやミラー等の光学素子は高精
度化する傾向にある。そのため、光学素子の面形状を測
定する面形状測定装置にも高い精度が求められている。2. Description of the Related Art In recent years, with the demand for high-precision optical instruments,
Optical elements such as lenses and mirrors that constitute such equipment tend to be highly accurate. Therefore, high accuracy is also required for a surface shape measuring device that measures the surface shape of an optical element.
【０００３】高精度な面形状測定を実現するものとして
光の干渉を利用した光波干渉計がある。特に、共通光路
干渉計であり、高い安定性が得られるフィゾー型の干渉
計が多く用いられている。There is a light wave interferometer that utilizes light interference to realize highly accurate surface shape measurement. In particular, a Fizeau-type interferometer, which is a common optical path interferometer and provides high stability, is widely used.
【０００４】フィゾー干渉計は、まず、光源から射出さ
れた光束を２つの光束に分割する。次に、一方の光束を
被検面へ入射、反射させて測定用光束とする。測定用光
束は被検面の面形状に応じて位相が変化している。ま
た、他方の光束は参照面で反射され参照用光束とする。
そして、測定用光束と参照用光束とを互いに干渉させて
干渉縞を形成する。最後に、この干渉縞に基づいて所定
の解析、演算を行って被検面の面形状を測定する。[0004] The Fizeau interferometer first splits a light beam emitted from a light source into two light beams. Next, one of the light beams enters the surface to be measured and is reflected to be a measurement light beam. The phase of the measurement light beam changes according to the shape of the surface to be measured. Further, the other light beam is reflected on the reference surface to be a reference light beam.
Then, the measurement light beam and the reference light beam are caused to interfere with each other to form interference fringes. Finally, predetermined analysis and calculation are performed based on the interference fringes to measure the surface shape of the test surface.
【０００５】従来の上記フィゾー干渉計では、参照面
（フィゾー面）を有するフィゾーレンズに径の大きい光
束を入射させて、実質的にフィゾーレンズ自身が絞りの
役割を兼用する構成とする場合が多い。さらには、フィ
ゾー干渉計における絞りの位置が全く考慮されず、任意
の位置に絞りを設ける場合も多い。In the conventional Fizeau interferometer, a large-diameter light beam is incident on a Fizeau lens having a reference surface (Fizeau surface), and the Fizeau lens itself often serves also as a diaphragm. . Further, the position of the diaphragm in the Fizeau interferometer is not considered at all, and the diaphragm is often provided at an arbitrary position.
【０００６】[0006]
【発明が解決しようとする課題】しかし、上述のように
フィゾーレンズ自身が絞りの役割を兼用する場合、又は
フィゾー干渉計における絞りの位置が全く考慮されず、
任意の位置に絞りを設けた場合は、この絞りに起因する
回折現象による波面の乱れが、絞りを通過した光束の周
辺部に生じてしまう。特に、被検面周辺部においてフレ
ネル回折による波面の乱れが観察される干渉縞に重畳し
てしまう。このため、高精度に面形状測定を行うことが
困難になり問題である。従来は、絞りによる回折の影響
を避けるため、被検面の周辺部の測定データを切り捨て
ることも行われている。この場合、被検面周辺部の形状
を測定することが不可能となってしまう。このことは、
特に曲率半径の小さな被検面の測定を行う際に深刻な問
題となるものである。However, as described above, when the Fizeau lens itself also serves as the stop, or the position of the stop in the Fizeau interferometer is not considered at all,
When a stop is provided at an arbitrary position, a wavefront disturbance due to a diffraction phenomenon caused by the stop occurs in a peripheral portion of a light beam passing through the stop. In particular, disturbance of the wavefront due to Fresnel diffraction is superimposed on the observed interference fringes in the periphery of the test surface. For this reason, it is difficult to measure the surface shape with high accuracy, which is a problem. Conventionally, in order to avoid the influence of diffraction caused by a diaphragm, measurement data of a peripheral portion of a surface to be measured has been cut off. In this case, it becomes impossible to measure the shape of the periphery of the test surface. This means
This is a serious problem particularly when measuring a test surface having a small radius of curvature.
【０００７】本発明は上記問題に鑑みてなされたもので
あり、レンズ、ミラーなどの光学素子の面形状を高精度
に測定できる面形状測定装置等を提供することを目的と
する。The present invention has been made in view of the above problems, and has as its object to provide a surface shape measuring apparatus and the like capable of measuring the surface shape of an optical element such as a lens or a mirror with high accuracy.
【０００８】[0008]
【課題を解決するための手段】上記課題を解決するため
に、本発明は、光源から出射された光であって、被検面
８ａからの反射光である測定光と、参照面７ａからの反
射光である参照光とを互いに干渉させ、該干渉による位
相差を検出することにより、前記被検面８ａの面形状を
測定する面形状測定装置において、前記被検面８ａと共
役な位置に絞り３が設けられていることを特徴とする面
形状測定装置を提供する。In order to solve the above-mentioned problems, the present invention relates to a measuring light which is a light emitted from a light source and which is a reflected light from a test surface 8a and a light which is reflected from a reference surface 7a. In a surface shape measuring apparatus for measuring the surface shape of the test surface 8a by causing the reference light, which is the reflected light, to interfere with each other and detecting a phase difference due to the interference, at a position conjugate with the test surface 8a. Provided is a surface shape measuring device provided with an aperture 3.
【０００９】また、本発明の好ましい態様では、前記絞
り３は、調整部材３０を備えていることが望ましい。Further, in a preferred embodiment of the present invention, it is desirable that the diaphragm 3 has an adjusting member 30.
【００１０】また、本発明の好ましい態様では、前記調
整部材３０は、前記被検面８ａと共役な位置へ前記絞り
３を移動する絞り移動部３０であることが望ましい。In a preferred aspect of the present invention, it is desirable that the adjusting member 30 is a diaphragm moving unit 30 that moves the diaphragm 3 to a position conjugate with the surface 8a to be inspected.
【００１１】また、本発明の好ましい態様では、前記調
整部材３０は、複数の反射ミラー部１２と、前記絞り３
と前記被検面８ａとが共役となるように該反射ミラー部
１２を移動するミラー移動部５０とからなることが望ま
しい。In a preferred embodiment of the present invention, the adjusting member 30 includes a plurality of reflecting mirrors 12 and the diaphragm 3.
And a mirror moving unit 50 that moves the reflection mirror unit 12 so that the surface 8a is conjugate with the surface 8a.
【００１２】また、本発明は、請求項１乃至４の何れか
１項に記載の面形状測定装置を用いて測定されたことを
特徴とする光学部材を提供する。Further, the present invention provides an optical member characterized by being measured by using the surface shape measuring device according to any one of claims 1 to 4.
【００１３】なお、本発明の構成を説明する上記課題を
解決するための手段の項では、本発明を分かり易くする
ために発明の実施の形態の図を用いたが、これにより本
発明が実施の形態に限定されるものではない。In the meantime, in the section of the means for solving the above-mentioned problem which explains the constitution of the present invention, the drawings of the embodiments of the present invention are used to make the present invention easy to understand. However, the present invention is not limited to this.
【００１４】[0014]
【発明の実施の形態】以下、添付図面に基づいて本発明
の各実施形態について説明する。Embodiments of the present invention will be described below with reference to the accompanying drawings.
【００１５】（第１の実施形態）図１は、本発明の第１
の実施形態に係る面形状測定装置の概略構成図である。
レーザ光源１は、直線偏光された光ビームＬを射出す
る。ビームエキスパンダ２は、光ビームＬのビーム径を
変換する。この光ビームＬは、絞り３を通過し、その光
束径を制限される。絞り３は、移動機構３０により光軸
ＡＸ方向に移動可能である。後述するように、移動機構
３０によって絞り３は被検面８ａと共役となるような位
置に調整されている。(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
It is a schematic structure figure of a surface profile measuring device concerning an embodiment.
The laser light source 1 emits a linearly polarized light beam L. The beam expander 2 converts the beam diameter of the light beam L. This light beam L passes through the stop 3 and its beam diameter is restricted. The diaphragm 3 is movable in the optical axis AX direction by the moving mechanism 30. As will be described later, the diaphragm 3 is adjusted to a position conjugate with the surface 8a to be measured by the moving mechanism 30.
【００１６】絞り３によって光束径を制限された光ビー
ムＬは、偏光ビームスプリッター（以下、「ＰＢＳ」と
いう。）４に入射する。光ビームＬの偏光面はＰＢＳ４
で反射されるように選択されている。ＰＢＳ４で反射さ
れた光ビームＬは、１／４波長板５及びビームエキスパ
ンダ６を経てフィゾーレンズ７へ入射する。フィゾーレ
ンズ７のフィゾー面（参照面）７ａからの反射光は参照
用光束ＬＲとして用いられる。また、フィゾー面７ａを
透過した光は測定用光束ＬＭとして、被検物８に入射す
る。The light beam L whose light beam diameter is limited by the stop 3 is incident on a polarizing beam splitter (hereinafter, referred to as “PBS”) 4. The polarization plane of the light beam L is PBS4
Is selected to be reflected by The light beam L reflected by the PBS 4 enters the Fizeau lens 7 via the quarter-wave plate 5 and the beam expander 6. The reflected light from the Fizeau surface (reference surface) 7a of the Fizeau lens 7 is used as a reference light beam LR. The light transmitted through the Fizeau surface 7a enters the test object 8 as a measurement light beam LM.
【００１７】まず、参照用光束ＬＲについて説明する。
参照用光束ＬＲは、フィゾー面７ａで反射した後、再び
ビームエキスパンダ６と１／４波長板５とを経てＰＢＳ
４に入射する。参照用光束ＬＲは、往復で１／４波長板
５を２度通過することによって偏光面が９０度回転する
ので、復路でＰＢＳ４を透過する。次に、ビーム径変換
光学系９でビーム径を変換され、２次元画像検出器１０
に入射する。First, the reference light beam LR will be described.
After being reflected by the Fizeau surface 7a, the reference light beam LR passes through the beam expander 6 and the quarter-wave plate 5 again, and the PBS.
4 is incident. The reference light beam LR passes through the quarter-wave plate 5 twice in a reciprocating manner, so that the polarization plane is rotated by 90 degrees. Therefore, the reference light beam LR passes through the PBS 4 on the return path. Next, the beam diameter is converted by the beam diameter conversion optical system 9 and the two-dimensional image detector 10
Incident on.
【００１８】一方、フィゾー面７ａの透過光は測定用光
束ＬＭとして用いられる。測定用光束ＬＭは、所定の位
置に配置された被検物８の被検面８ａに入射する。そし
て、被検面８ａの面形状に対応して測定用光束ＬＭの位
相が変化し、反射される。被検面８ａから反射してきた
測定用光束ＬＭは、再びフィゾーレンズ７、ビームエキ
スパンダ６，１／４波長板５を経てＰＢＳ４へ入射す
る。この測定用光束ＬＭは、参照用光束ＬＲと同様に、
往復で１／４波長板５を２度通過することによって偏光
面が９０度回転するので、復路でＰＢＳ４を透過する。
そして、ビーム径変換光学系９でビーム径を変換され
る。最後に、２次元画像検出器１０に入射する。２次元
画像検出器１０の撮像面１０ａ上では、参照用光束ＬＲ
と測定用光束ＬＭとの干渉縞が検出される。On the other hand, the light transmitted through the Fizeau surface 7a is used as a measuring light beam LM. The measurement light beam LM is incident on a test surface 8a of the test object 8 arranged at a predetermined position. Then, the phase of the measurement light beam LM changes according to the surface shape of the test surface 8a and is reflected. The measurement light beam LM reflected from the test surface 8a is incident on the PBS 4 again through the Fizeau lens 7, the beam expander 6, and the quarter-wave plate 5. This measurement light beam LM is similar to the reference light beam LR,
The polarization plane is rotated 90 degrees by passing through the quarter-wave plate 5 twice in a reciprocating manner, so that the light passes through the PBS 4 on the return path.
Then, the beam diameter is converted by the beam diameter conversion optical system 9. Finally, the light enters the two-dimensional image detector 10. On the imaging surface 10a of the two-dimensional image detector 10, the reference light beam LR
An interference fringe between the light beam and the measuring light beam LM is detected.
【００１９】なお、ビーム径変換光学系９は、移動部９
０により光軸ＡＸ方向に移動可能である。移動部９０
は、コンピュータＰＣからの信号に基づいて、被検面８
ａの像が２次元画像検出器１０の撮像面１０ａに結像す
る位置へビーム径変換光学系９を移動する。即ち、ビー
ム径変換光学系９は、ビーム径を変換する役割に加え
て、被検面８ａの像を２次元画像検出器１０の撮像面１
０ａ上に結像させる役割をも有している。Note that the beam diameter conversion optical system 9 includes a moving unit 9.
By 0, it can be moved in the optical axis AX direction. Moving unit 90
Is based on a signal from the computer PC.
The beam diameter conversion optical system 9 is moved to a position where the image a is formed on the imaging surface 10a of the two-dimensional image detector 10. That is, the beam diameter conversion optical system 9 not only serves to convert the beam diameter, but also converts the image of the test surface 8a to the image pickup surface 1 of the two-dimensional image detector 10.
Also, it has a role of forming an image on 0a.
【００２０】２次元画像検出器１０からの出力は、コン
ピュータＰＣに取り込まれて解析され、干渉縞の位相分
布が算出される。その演算結果はメモリＭＲに記憶され
る。The output from the two-dimensional image detector 10 is taken into a computer PC and analyzed, and the phase distribution of interference fringes is calculated. The operation result is stored in the memory MR.
【００２１】なお、本実施形態の面形状測定装置では、
被検物８をピエゾ素子ＰＺＴで光軸ＡＸ方向に微小に移
動させ、周知の位相シフト干渉法を用いて干渉縞の位相
分布を高精度に求めることが望ましい。In the surface shape measuring apparatus of this embodiment,
It is desirable that the test object 8 be minutely moved in the direction of the optical axis AX by the piezo element PZT, and the phase distribution of the interference fringes be determined with high precision using a well-known phase shift interferometry.
【００２２】上述したように、絞り３は、移動機構３０
によって被検面８ａと共役となるような位置に調整され
ている。この調整の手順としては、例えば、以下の
（１）又は（２）の手順を挙げることができる。 （１）コンピュータＰＣは、被検面８ａの曲率半径等の
データから被検面８ａの位置を算出する。次に、光線追
跡により被検面８ａと共役になる絞り３の所定位置を算
出する。そして、移動機構３０は、コンピュータＰＣか
らの信号に従い、絞り３を所定位置へ移動させる。 （２）測定位置に置かれた被検面８ａにマスクを設け
る。そして、ビーム径変換光学系９は、撮像部１０の撮
像面１０ａにおいて該マスクにピントが合うようレンズ
群が移動する。次に、マスクを被検面８ａから取り除
く。移動機構３０は、被検面８ａと絞り３とが共役とな
るように、即ち被検面８ａの像と絞り３の像とが撮像面
１０ａに結像するように絞り３を移動する。As described above, the stop 3 is moved by the moving mechanism 30.
Is adjusted to a position conjugate with the surface 8a to be inspected. As the procedure for this adjustment, for example, the following procedure (1) or (2) can be mentioned. (1) The computer PC calculates the position of the test surface 8a from data such as the radius of curvature of the test surface 8a. Next, a predetermined position of the stop 3 which is conjugate with the surface 8a to be detected is calculated by ray tracing. Then, the moving mechanism 30 moves the diaphragm 3 to a predetermined position according to a signal from the computer PC. (2) A mask is provided on the test surface 8a placed at the measurement position. Then, in the beam diameter conversion optical system 9, the lens group moves so that the mask is focused on the imaging surface 10a of the imaging unit 10. Next, the mask is removed from the test surface 8a. The moving mechanism 30 moves the diaphragm 3 so that the surface 8a to be measured and the diaphragm 3 are conjugate, that is, the image of the surface 8a to be measured and the image of the diaphragm 3 are formed on the imaging surface 10a.
【００２３】以上に述べたように、絞り３と被検面８ａ
とが共役である構成とすることによって絞り３の像が被
検面８ａに形成される。また、被検面８ａの像は２次元
画像検出器１０の撮像面１０ａに形成される。あたかも
被検面８ａ上に絞りがあるかのように周辺部の波面の乱
れの領域を最小にすることができる。このため、本実施
形態に係る面形状測定装置は、絞り３での回折現象、特
にフレネル回折による波面の乱れを最小限に抑えること
ができるという効果が得られる。その結果、参照用光束
と測定用光束との干渉縞の位相分布を高精度に求めるこ
とが可能となるので高精度に面形状を測定することがで
きる。 （第２の実施形態）図２は、本発明の第２の実施形態に
係る面形状測定装置の概略構成図である。本実施形態に
係る面形状測定装置は、第１の実施形態における絞り３
をＰＢＳ４とビームエキスパンダ６との間に配置したも
のである。その他の構成は上記第１実施形態と同様であ
るので同一部分には同じ符号を付し、重複する説明は省
略する。As described above, the stop 3 and the test surface 8a
Is conjugated, an image of the stop 3 is formed on the surface 8a to be inspected. Further, an image of the test surface 8a is formed on the imaging surface 10a of the two-dimensional image detector 10. It is possible to minimize the disturbance area of the wavefront in the peripheral portion as if there is a stop on the test surface 8a. For this reason, the surface shape measuring apparatus according to the present embodiment has an effect that the diffraction phenomenon at the diaphragm 3, in particular, the disturbance of the wavefront due to Fresnel diffraction can be minimized. As a result, the phase distribution of the interference fringes between the reference light beam and the measurement light beam can be obtained with high accuracy, so that the surface shape can be measured with high accuracy. (Second Embodiment) FIG. 2 is a schematic configuration diagram of a surface shape measuring apparatus according to a second embodiment of the present invention. The surface shape measuring apparatus according to the present embodiment is the same as the stop 3 in the first embodiment.
Are arranged between the PBS 4 and the beam expander 6. Other configurations are the same as those of the first embodiment, and thus the same portions are denoted by the same reference numerals, and overlapping description will be omitted.
【００２４】上記第１実施形態に述べた手順と同様に、
移動機構３０は絞り３を光軸ＡＸ方向に移動することが
できる。そして、絞り３は、移動機構３０により被検面
８ａと共役となる位置に調整されている。 （第３の実施形態）図３は、本発明の第３の実施形態に
係る面形状測定装置の概略構成図である。本実施形態に
係る面形状測定装置では、上記第２の実施形態と同様の
位置に絞り３が固定して設けられている。更に、該絞り
３とビームエキスパンダ６との間に、反射ミラー１１
ａ，１１ｂと、２枚の反射面どうしが略９０度をなすよ
うに構成された２枚反射ミラー部１２とから成る反射ミ
ラー光学系ＭＭが設けられている。その他の構成は上記
第１，２の実施形態と同様であるので同一部分には同じ
符号を付し、重複する説明は省略する。Similar to the procedure described in the first embodiment,
The moving mechanism 30 can move the stop 3 in the optical axis AX direction. The diaphragm 3 is adjusted by the moving mechanism 30 to a position conjugate with the surface 8a to be inspected. (Third Embodiment) FIG. 3 is a schematic configuration diagram of a surface shape measuring apparatus according to a third embodiment of the present invention. In the surface shape measuring device according to the present embodiment, the stop 3 is fixedly provided at the same position as in the second embodiment. Further, a reflection mirror 11 is provided between the stop 3 and the beam expander 6.
There is provided a reflection mirror optical system MM including the reflection mirrors a and 11b and two reflection mirror portions 12 configured such that two reflection surfaces form substantially 90 degrees. Other configurations are the same as those of the first and second embodiments, and thus the same portions are denoted by the same reference numerals, and overlapping description will be omitted.
【００２５】反射ミラー光学系ＭＭのうち、２枚反射ミ
ラー部１２は移動機構５０により、図３中の矢印方向に
移動可能である。コンピュータＰＣは、上記第１の実施
形態において述べた絞り３と被検面８ａとを共役な位置
にする手順（１）又は（２）に従って、絞り３と被検面
８ａとが共役になるように２枚反射ミラー部１２を移動
させる。これにより、被検面８ａと絞り３との間の光路
長を変化させることができる。The two-reflection mirror section 12 of the reflection mirror optical system MM can be moved in the direction of the arrow in FIG. According to the procedure (1) or (2) for setting the stop 3 and the surface 8a to be conjugate to each other as described in the first embodiment, the computer PC causes the stop 3 and the surface 8a to be conjugated. Then, the two-reflection mirror section 12 is moved. Thereby, the optical path length between the test surface 8a and the stop 3 can be changed.
【００２６】また、リレーレンズ系１３が、ビームエキ
スパンダ６と反射ミラー光学系ＭＭとの間に配置されて
いる。このリレーレンズ系１３は、反射ミラー光学系Ｍ
Ｍを光路中に設けた状態で像の共役位置をリレーする役
割を有する。A relay lens system 13 is provided between the beam expander 6 and the reflection mirror optical system MM. The relay lens system 13 includes a reflecting mirror optical system M
It has the role of relaying the conjugate position of the image with M provided in the optical path.
【００２７】ここで、上述したように上記第１，２実施
形態におけるビーム径変換光学系９は、被検面８ａの像
を２次元画像検出器１０の撮像面１０ａに結像する役割
も兼ねている。一方、本実施形態では絞り３をＰＢＳ４
とビームエキスパンダ６との間に固定配置している。こ
のため、ビーム径変換光学系９は、絞り３と２次元画像
検出器１０の撮像面１０ａとを共役にする位置に固定す
ることができる。これにより上記第１，２実施形態に係
る面形状測定装置の効果に加え、ビーム径変換光学系９
を可動にする必要がないので、可動部分を少なくできる
という効果を奏する。Here, as described above, the beam diameter converting optical system 9 in the first and second embodiments also has a role of forming an image of the test surface 8a on the imaging surface 10a of the two-dimensional image detector 10. ing. On the other hand, in this embodiment, the diaphragm 3 is
And a beam expander 6. For this reason, the beam diameter conversion optical system 9 can be fixed at a position where the stop 3 and the imaging surface 10a of the two-dimensional image detector 10 are conjugate. Accordingly, in addition to the effects of the surface shape measuring devices according to the first and second embodiments, the beam diameter conversion optical system 9
Since it is not necessary to make the movable part movable, the effect that the movable part can be reduced can be achieved.
【００２８】さらに、ビーム変換光学系９が移動可能な
場合は、その移動に応じて被検面８ａの横座標と、撮像
面１０ａの横座標との対応関係が変化してしまうおそれ
がある。本実施形態では、ビーム変換光学系９が固定で
あるので、この対応関係を常に一定にできるという効果
が得られる。Further, when the beam conversion optical system 9 is movable, the correspondence between the abscissa of the test surface 8a and the abscissa of the imaging surface 10a may change in accordance with the movement. In the present embodiment, since the beam conversion optical system 9 is fixed, an effect is obtained that this correspondence can be always kept constant.
【００２９】なお、本実施形態において、反射ミラー光
学系ＭＭはＰＢＳ４とビームエキスパンダ６との間に設
置している。しかし、これに限られるものではなく、反
射ミラー光学系ＭＭは、第１実施形態の構成にも適用で
きる。この場合、絞り３とＰＢＳ４との間に反射ミラー
光学系ＭＭを配置し、絞り３を固定する構成にしてもよ
い。In this embodiment, the reflection mirror optical system MM is installed between the PBS 4 and the beam expander 6. However, the present invention is not limited to this, and the reflection mirror optical system MM can be applied to the configuration of the first embodiment. In this case, the reflection mirror optical system MM may be arranged between the stop 3 and the PBS 4 to fix the stop 3.
【００３０】さらに、上記第１〜第３の実施形態では、
本発明をフィゾー干渉計へ適用した例を示しているが、
本発明はトワイマングリーン干渉計等、他の方式の干渉
計にも適用できるものである。Further, in the first to third embodiments,
Although an example in which the present invention is applied to a Fizeau interferometer is shown,
The present invention can also be applied to other types of interferometers, such as the Twyman Green interferometer.
【００３１】また、本発明によれば、上記各実施形態に
かかる面形状測定装置を用いて光学部材、例えば投影露
光装置に用いられる投影レンズ系に組み込まれる投影レ
ンズを製造できる。これにより高精度な光学部材を提供
できるという効果を奏する。Further, according to the present invention, an optical member, for example, a projection lens incorporated in a projection lens system used in a projection exposure apparatus can be manufactured using the surface shape measuring apparatus according to each of the above embodiments. This produces an effect that a highly accurate optical member can be provided.
【００３２】[0032]
【発明の効果】以上説明したように本発明によれば、絞
りでの回折による波面の乱れを最小限に抑えることがで
きる。その結果、参照用光束と測定用光束との干渉縞の
位相分布を高精度に求めることが可能となる。これによ
り、レンズ、ミラーなどの光学素子の面形状を高精度に
測定できる面形状測定装置等を提供できる。特に、回折
の影響を受けやすかった曲率半径の小さな被検面を高精
度に測定できる面形状測定装置を提供できる。As described above, according to the present invention, disturbance of the wavefront due to diffraction at the stop can be minimized. As a result, the phase distribution of the interference fringes between the reference light beam and the measurement light beam can be obtained with high accuracy. This makes it possible to provide a surface shape measuring device or the like capable of measuring the surface shape of an optical element such as a lens or a mirror with high accuracy. In particular, it is possible to provide a surface shape measuring apparatus capable of measuring a test surface having a small radius of curvature, which is easily affected by diffraction, with high accuracy.
【図１】本発明の第１実施形態に係る面形状測定装置の
概略構成図である。FIG. 1 is a schematic configuration diagram of a surface shape measuring device according to a first embodiment of the present invention.
【図２】本発明の第２実施形態に係る面形状測定装置の
概略構成図である。FIG. 2 is a schematic configuration diagram of a surface shape measuring device according to a second embodiment of the present invention.
【図３】本発明の第３実施形態に係る面形状測定装置の
概略構成図である。FIG. 3 is a schematic configuration diagram of a surface shape measuring device according to a third embodiment of the present invention.
１…レーザ光源 ２，６…ビームエキスパンダ ３…絞り ４…ＰＢＳ ５…λ／４板 ７…フィゾーレンズ ７ａ…フィゾー面 ８…被検物 ８ａ…被検面 ９…ビーム径変換光学系 １０…２次元画像検出器 １０ａ…撮像面 １１ａ，１１ｂ…反射ミラー １２…２枚反射ミラー部 １３…リレーレンズ系 ３０，５０，９０…移動機構 ＡＸ…光軸 Ｌ…光ビーム ＬＭ…測定用光束 ＬＲ…参照用光束 ＰＺＴ…ピエゾ素子 ＰＣ…コンピュータ ＭＲ…メモリ ＭＭ…反射ミラー部 DESCRIPTION OF SYMBOLS 1 ... Laser light source 2, 6 ... Beam expander 3 ... Aperture 4 ... PBS 5 ... λ / 4 plate 7 ... Fizeau lens 7a ... Fizeau surface 8 ... Test object 8a ... Test surface 9 ... Beam diameter conversion optical system 10 ... Two-dimensional image detector 10a Image pickup surface 11a, 11b Reflective mirror 12 Two-reflective mirror unit 13 Relay lens system 30, 50, 90 Moving mechanism AX Optical axis L Light beam LM Measurement light flux LR Reference beam PZT: Piezo element PC: Computer MR: Memory MM: Reflection mirror
フロントページの続き Ｆターム(参考） 2F064 AA09 BB05 CC04 EE05 FF01 GG00 GG23 GG38 GG44 GG58 GG68 JJ01 KK01 2F065 AA53 BB25 CC22 DD03 FF42 GG04 JJ03 JJ26 LL04 LL09 LL30 LL36 LL37 LL57 MM02 PP12 UU07 2G086 FF01 GG01 Continued on the front page F term (reference) 2F064 AA09 BB05 CC04 EE05 FF01 GG00 GG23 GG38 GG44 GG58 GG68 JJ01 KK01 2F065 AA53 BB25 CC22 DD03 FF42 GG04 JJ03 JJ26 LL04 LL09 LL30 LL36 LL37 LL37 LL37 LL37
Claims (5)
らの反射光である測定光と、参照面からの反射光である
参照光とを互いに干渉させ、該干渉による位相差を検出
することにより、前記被検面の面形状を測定する面形状
測定装置において、 前記被検面と共役な位置に絞りが設けられていることを
特徴とする面形状測定装置。1. A light emitted from a light source, the measurement light being reflected light from a surface to be measured and the reference light being reflected light from a reference surface are caused to interfere with each other, and a phase difference caused by the interference is reduced. A surface shape measuring device for measuring the surface shape of the surface to be detected by detecting, wherein an aperture is provided at a position conjugate with the surface to be measured.
特徴とする請求項１に記載の面形状測定装置。2. The surface shape measuring apparatus according to claim 1, wherein said stop has an adjusting member.
へ前記絞りを移動する絞り移動部であることを特徴とす
る請求項２に記載の面形状測定装置。3. The surface shape measuring apparatus according to claim 2, wherein the adjustment member is a diaphragm moving unit that moves the diaphragm to a position conjugate with the surface to be inspected.
前記絞りと前記被検面とが共役となるように該反射ミラ
ー部を移動するミラー移動部とからなることを特徴とす
る請求項２に記載の面形状測定装置。4. An adjusting member comprising: a plurality of reflecting mirrors;
The surface shape measuring apparatus according to claim 2, further comprising a mirror moving unit that moves the reflection mirror unit so that the stop and the surface to be measured are conjugate.
状測定装置を用いて測定されたことを特徴とする光学部
材。5. An optical member measured using the surface shape measuring device according to claim 1. Description:
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000398968A JP2002202104A (en) | 2000-12-27 | 2000-12-27 | Face shape measuring device and optical member measured thereby |
| US10/024,145 US20020080366A1 (en) | 2000-12-27 | 2001-12-21 | Apparatus for measuring surface shape, lateral coordinate calibration method therefor, and optical member having been measured with said apparatus or method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000398968A JP2002202104A (en) | 2000-12-27 | 2000-12-27 | Face shape measuring device and optical member measured thereby |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2002202104A true JP2002202104A (en) | 2002-07-19 |
Family
ID=18863824
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000398968A Withdrawn JP2002202104A (en) | 2000-12-27 | 2000-12-27 | Face shape measuring device and optical member measured thereby |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2002202104A (en) |
-
2000
- 2000-12-27 JP JP2000398968A patent/JP2002202104A/en not_active Withdrawn
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