JPH0566377A - Optical device - Google Patents
Optical deviceInfo
- Publication number
- JPH0566377A JPH0566377A JP22787091A JP22787091A JPH0566377A JP H0566377 A JPH0566377 A JP H0566377A JP 22787091 A JP22787091 A JP 22787091A JP 22787091 A JP22787091 A JP 22787091A JP H0566377 A JPH0566377 A JP H0566377A
- Authority
- JP
- Japan
- Prior art keywords
- liquid crystal
- crystal element
- phase
- amplitude
- modulation
- 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.)
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- Liquid Crystal (AREA)
- Diffracting Gratings Or Hologram Optical Elements (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、液晶素子を応用した光
学装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device to which a liquid crystal element is applied.
【０００２】[0002]
【従来の技術】従来、光波面の位相分布を補正する目的
には、１枚続きのミラーの形状を裏からアクチュエータ
で変形させる方式が広く利用されていた。変形させるア
クチュエータにはピエゾ素子が使われ、ストロークが数
μｍ、個数が５００個程度のものが試作されている（例
えば、Ｐｒｏｃ．ＳＰＩＥ，Ｖｏｌ．１１１４，ｐ１３
４（１９８９）参照）。2. Description of the Related Art Conventionally, for the purpose of correcting the phase distribution of a light wave front, a method of deforming the shape of a continuous mirror with an actuator from the back has been widely used. A piezo element is used as the actuator to be deformed, and a prototype having a stroke of several μm and a number of about 500 is manufactured (for example, Proc. SPIE, Vol. 1114, p13).
4 (1989)).
【０００３】[0003]
【発明が解決しようとする課題】しかし、ピエゾ素子に
は、発熱、ヒステリシスなどの制御に工夫がいる、素子
数が限られている、駆動電圧が高いなどの問題点があっ
た。However, the piezo element has problems such as ingenuity in controlling heat generation and hysteresis, a limited number of elements, and high driving voltage.
【０００４】本発明はこのような問題点を解決するもの
であって、その目的は、簡便な手段により光波面の位相
分布を測定、補正して、かつ同時に光波面の振幅分布を
補正することができる光学装置を提供するところにあ
る。The present invention solves such a problem, and an object thereof is to measure and correct the phase distribution of the light wave front by a simple means and simultaneously correct the amplitude distribution of the light wave front. An optical device capable of performing the above is provided.
【０００５】[0005]
【課題を解決するための手段】本発明の第１の光学装置
は、液晶素子と、前記液晶素子の駆動回路と、光波面の
位相分布を測定する手段と、前記光波面を測定する手段
により得られた信号を前記液晶素子の駆動回路へ帰還す
る回路を備えて成ることを特徴とする。A first optical device of the present invention comprises a liquid crystal element, a drive circuit for the liquid crystal element, a means for measuring a phase distribution of a light wave front, and a means for measuring the light wave front. It is characterized by comprising a circuit for feeding back the obtained signal to the drive circuit of the liquid crystal element.
【０００６】本発明の第２の光学装置は、前記第１の光
学装置において、振幅変調用液晶素子と、位相変調用液
晶素子と、前記複数の液晶素子の駆動回路を備えて成る
ことを特徴とする。According to a second optical device of the present invention, in the first optical device, an amplitude modulation liquid crystal element, a phase modulation liquid crystal element, and a drive circuit for the plurality of liquid crystal elements are provided. And
【０００７】本発明の第３の光学装置は、前記第１ない
し第２の光学装置において、振幅変調用液晶素子と位相
変調用液晶素子の間にアフォーカル光学系を備え、前記
振幅変調用液晶素子と前記位相変調用液晶素子が前記ア
フォーカル光学系において互いに共役な関係で配置され
て成ることを特徴とする。According to a third optical device of the present invention, in the first or second optical device, an afocal optical system is provided between the liquid crystal element for amplitude modulation and the liquid crystal element for phase modulation, and the liquid crystal for amplitude modulation is provided. The element and the liquid crystal element for phase modulation are arranged in a conjugate relationship with each other in the afocal optical system.
【０００８】[0008]
【実施例】以下では実施例にもとづき、本発明の内容に
ついて詳しく説明する。EXAMPLES The contents of the present invention will be described in detail below based on examples.
【０００９】（実施例１）直線偏光レーザビームの波面
補正を例にあげる。図１に本実施例の光学装置の構成を
示す。補正されるべきレーザビームａは、振幅変調用液
晶素子１０１で振幅変調を受けた後に、位相変調用液晶
素子１０５で位相変調を受ける。これらふたつの液晶素
子は、レンズ１０２とレンズ１０４から構成されるアフ
ォーカル光学系により、互いに共役に接続されている。
空間フィルタ１０３は、ビームが液晶素子を透過する時
に発生する高次回折成分を除くために配置されている。
液晶素子を透過したビームは、ミラー１０６により一部
は収差測定系１０７へ導かれる。残りは振幅分布ならび
に位相分布が補正されたビームｂとなって装置の外へ出
てゆく。収差測定系１０７ならびに液晶素子の駆動回路
１０９は、コンピュータ１０８に接続されている。(Embodiment 1) Wavefront correction of a linearly polarized laser beam will be described as an example. FIG. 1 shows the configuration of the optical device of this embodiment. The laser beam a to be corrected is subjected to amplitude modulation by the amplitude modulation liquid crystal element 101 and then undergoes phase modulation by the phase modulation liquid crystal element 105. These two liquid crystal elements are connected to each other conjugately by an afocal optical system including a lens 102 and a lens 104.
The spatial filter 103 is arranged to remove higher-order diffraction components generated when the beam passes through the liquid crystal element.
A part of the beam transmitted through the liquid crystal element is guided to the aberration measurement system 107 by the mirror 106. The remaining beam becomes a beam b whose amplitude distribution and phase distribution are corrected and goes out of the apparatus. The aberration measurement system 107 and the liquid crystal element drive circuit 109 are connected to a computer 108.
【００１０】液晶素子の駆動回路には、装置の用途に合
わせて、補正情報を入力する。たとえば、ガウス関数形
の振幅分布を与える補正情報を振幅変調用液晶素子１０
１へ入力し、同時に、光波面、レンズ系および液晶素子
の各収差の総和に対して複素共役な位相分布を与える補
正情報を位相変調用液晶素子１０５へ入力する。こうす
ると、ビームを回折限界近くまで絞ることができる。こ
の他にも、計算機ホログラムの手法を用いて前記補正情
報の作り方を工夫することにより、集光スポットを複数
発生させたり、任意の集光強度分布を得ることができる
（第５１回応用物理学会学術講演会予稿集２６ａ−Ｈ−
１０）。振幅分布に関する補正情報およびレンズ系や液
晶素子の各収差から求めた位相分布に関する補正情報
は、あらかじめコンピュータに接続されたメモリ１１０
に格納しておいてもよい。Correction information is input to the drive circuit of the liquid crystal element according to the application of the device. For example, correction information that gives a Gaussian function type amplitude distribution is provided with the amplitude modulation liquid crystal element 10.
1, and at the same time, correction information that gives a complex conjugate phase distribution to the total sum of aberrations of the light wavefront, the lens system, and the liquid crystal element is input to the phase modulation liquid crystal element 105. This allows the beam to be narrowed to near the diffraction limit. In addition to this, it is possible to generate a plurality of converging spots and obtain an arbitrary condensing intensity distribution by devising a method of creating the correction information by using a computer hologram method (The 51st Japan Society of Applied Physics) Academic Lecture Proceedings 26a-H-
10). The correction information about the amplitude distribution and the correction information about the phase distribution obtained from each aberration of the lens system and the liquid crystal element are stored in the memory 110 connected to the computer in advance.
It may be stored in.
【００１１】収差測定系１０７はレンズアレイと光検出
器を備え、集光スポットの位置から光波面の収差を測定
する。そして、測定の結果をもとに、位相変調用液晶素
子１０５の各画素へ加えるべき電圧値を算出して、これ
を補正情報として駆動回路１０９へ帰還する。駆動回路
は、受け取った補正情報にしたがって、通過する光の位
相を画素単位で制御する。光波面の収差の測定には、ジ
ャックハルトマン法（Ｐｕｂｌ．Ｎａｔ．Ａｓｔｒｏ
ｎ．Ｏｂｓ．，Ｖｏｌ．１，ｐ４９（１９８９）参照）
やロジェ法（Ｐｒｏｃ．ＳＰＩＥ，Ｖｏｌ．１１１４，
ｐ９２（１９８９）参照）が用いられる。The aberration measuring system 107 comprises a lens array and a photodetector, and measures the aberration of the light wavefront from the position of the focused spot. Then, the voltage value to be applied to each pixel of the phase modulation liquid crystal element 105 is calculated based on the measurement result, and the calculated voltage value is fed back to the drive circuit 109 as correction information. The drive circuit controls the phase of the passing light in pixel units according to the received correction information. The Jack Hartmann method (Publ. Nat. Astro) is used to measure the aberration of the light wavefront.
n. Obs. , Vol. 1, p49 (1989)).
And Roger method (Proc. SPIE, Vol. 1114,
p92 (1989)) is used.
【００１２】本実施例には、ＴＮ（ツイストネマッティ
ック）モードの振幅変調用液晶素子と、ＥＣＢ（電界制
御複屈折）モードの位相変調用液晶素子を用いた。どち
らの液晶素子も、各画素にＴＦＴ（薄膜トランジスタ）
を備えたマトリクス駆動型の液晶素子であって、５ボル
ト程度の低い電圧で駆動できる。有効画素数は３２０×
２２０、画素間隔は水平方向８０μｍ、垂直方向９０μ
ｍである。In this embodiment, a TN (twisted nematic) mode amplitude modulation liquid crystal element and an ECB (electric field control birefringence) mode phase modulation liquid crystal element were used. Both liquid crystal elements have a TFT (thin film transistor) for each pixel.
It is a matrix-driving type liquid crystal element provided with, and can be driven by a low voltage of about 5 volts. 320 × effective pixels
220, the pixel interval is 80 μm in the horizontal direction, 90 μ in the vertical direction
m.
【００１３】位相変調液晶素子における液晶分子の配向
はホモジニアス配向であって、ビーム波面の位相を連続
的に変調することができる（第５１回応用物理学会学術
講演会予稿集２６ａ−Ｈ−１０）。ただし、ビームの直
線偏光方位を液晶分子の配向方向に合わせておく必要が
ある。なお、ビームがＴＮモードの液晶素子を通過する
時に受ける位相歪は（Ｊｐｎ．Ｊ．Ａｐｐｌ．Ｐｈｙ
ｓ．，２９，Ｌ１５３３（１９９０）参照）、ＥＣＢモ
ードの液晶素子を用いて補正する。The orientation of the liquid crystal molecules in the phase modulation liquid crystal element is a homogeneous orientation, and the phase of the beam wavefront can be continuously modulated (Proceedings of the 51st SPSJ Academic Conference 26a-H-10). .. However, it is necessary to align the linear polarization direction of the beam with the alignment direction of the liquid crystal molecules. The phase distortion that the beam receives when passing through a TN mode liquid crystal element is (Jpn.J.Appl.Phy.
s. , 29, L1533 (1990)), using an ECB mode liquid crystal element for correction.
【００１４】本実施例によれば、振幅変調用液晶素子と
位相変調用液晶素子を光学的に接続することにより、ビ
ーム波面の収差を補正すると同時に所望の振幅分布をビ
ームに与えることができる。液晶素子は低電圧駆動、低
消費電力、高画素密度という特徴を備えており、従来の
ピエゾ素子に比べて容易にビーム波面の位相を制御する
ことができる。According to this embodiment, by optically connecting the amplitude modulation liquid crystal element and the phase modulation liquid crystal element, it is possible to correct the aberration of the beam wavefront and at the same time give a desired amplitude distribution to the beam. The liquid crystal element has features of low voltage driving, low power consumption, and high pixel density, and the phase of the beam wavefront can be controlled more easily than the conventional piezo element.
【００１５】なお、振幅変調用液晶素子と位相変調用液
晶素子の順序を逆にして接続することも可能である。The amplitude modulation liquid crystal element and the phase modulation liquid crystal element may be connected in reverse order.
【００１６】（実施例２）ランダム偏光レーザビームの
波面補正を例にあげる。図２に本実施例の光学装置の構
成を示す。収差を含むランダム偏光なビームａは、偏光
ビームスプリッタ２０１で紙面に垂直な成分（Ｓ偏光）
と紙面に平行な成分（Ｐ偏光）に分かれる。それぞれの
成分は振幅変調用液晶素子２０２（または２０７）で振
幅変調を受けた後、位相変調用液晶素子２０６（または
２１１）で位相変調を受ける。振幅変調用液晶素子２０
２と位相変調用液晶素子２０６は、レンズ２０３とレン
ズ２０５から構成されるアフォーカル光学系により、他
方、振幅変調用液晶素子２０７と位相変調用液晶素子２
１１は、レンズ２０８とレンズ２１０から構成されるア
フォーカル光学系により、互いに共役に接続されてい
る。ミラー２０４、２０９は、それぞれ液晶素子２０
２、２０７を透過したビームの０次回折成分だけを反射
させるように、局所的に反射率が高く、それ以外の領域
には反射防止膜が付加されている。液晶素子を透過した
ビームは、偏光ビームスプリッタ２１２へ入射する。こ
こでふたつの成分は合成され、振幅分布ならびに位相分
布が補正されたビームｂとなって装置の外へ出てゆく。
ただし、ミラー１０６によりビームｂの一部は収差測定
系１０７へ導かれる。収差測定系１０７ならびに液晶素
子の駆動回路１０９は、コンピュータ１０８に接続され
ている。(Embodiment 2) The wavefront correction of a randomly polarized laser beam will be taken as an example. FIG. 2 shows the configuration of the optical device of this example. The randomly polarized beam a including aberration is a component (S polarization) perpendicular to the paper surface by the polarization beam splitter 201.
And a component (P polarized light) parallel to the paper surface. Each component undergoes amplitude modulation by the amplitude modulation liquid crystal element 202 (or 207) and then undergoes phase modulation by the phase modulation liquid crystal element 206 (or 211). Amplitude modulation liquid crystal element 20
2 and the liquid crystal element 206 for phase modulation use the afocal optical system composed of the lens 203 and the lens 205, while the liquid crystal element 207 for amplitude modulation and the liquid crystal element 2 for phase modulation are used.
Reference numeral 11 is conjugated with each other by an afocal optical system including a lens 208 and a lens 210. The mirrors 204 and 209 are respectively the liquid crystal element 20.
The reflectance is locally high so that only the 0th-order diffracted component of the beam transmitted through 2, 207 is reflected, and an antireflection film is added to the other regions. The beam transmitted through the liquid crystal element enters the polarization beam splitter 212. Here, the two components are combined into a beam b whose amplitude distribution and phase distribution have been corrected, and go out of the apparatus.
However, a part of the beam b is guided to the aberration measurement system 107 by the mirror 106. The aberration measurement system 107 and the liquid crystal element drive circuit 109 are connected to a computer 108.
【００１７】本実施例で使用した振幅変調用液晶素子お
よび位相変調用液晶素子は、実施例実１で使用したもの
と同じである。また、収差測定系の構成ならびに収差測
定方法も、互いに直交する直線偏光成分のそれぞれにつ
いて行う点を除いては実施例１と同様である。よって、
ここでは説明を省略する。The amplitude modulation liquid crystal element and the phase modulation liquid crystal element used in this embodiment are the same as those used in Embodiment 1. Further, the configuration of the aberration measurement system and the aberration measurement method are the same as those in the first embodiment except that the linearly polarized light components orthogonal to each other are performed. Therefore,
The description is omitted here.
【００１８】本実施例によれば、アフォーカル光学系で
接続された振幅変調用液晶素子と位相変調用液晶素子の
組を、互いに直交する直線偏光成分の各々に作用させる
ことによって、ランダム偏光なビーム波面の収差を補正
すると同時に所望の振幅分布をビームに与えることがで
きる。According to the present embodiment, the set of the liquid crystal element for amplitude modulation and the liquid crystal element for phase modulation connected by the afocal optical system is made to act on each of the linearly polarized light components which are orthogonal to each other, whereby a random polarized light is generated. It is possible to correct the aberration of the beam wavefront and at the same time give a desired amplitude distribution to the beam.
【００１９】[0019]
【発明の効果】本発明によれば、光波面の振幅と位相を
同時に補正することができる。本発明の光学装置は、液
晶素子のプログラム自在性を活用して、レーザビーム波
面制御に代表される補償光学へ幅広く応用が可能であ
る。According to the present invention, the amplitude and phase of the light wavefront can be corrected simultaneously. The optical device of the present invention can be widely applied to adaptive optics represented by laser beam wavefront control by utilizing the programmability of a liquid crystal element.
【図１】 本発明の実施例１の構成を示す平面図であ
る。FIG. 1 is a plan view showing a configuration of a first embodiment of the present invention.
【図２】 本発明の実施例２の構成を示す平面図であ
る。FIG. 2 is a plan view showing a configuration of a second embodiment of the present invention.
１０１・・・・・・マトリクス駆動型のＴＮモード液晶素子 １０２・・・・・・レンズ １０３・・・・・・空間フィルタ １０４・・・・・・レンズ １０５・・・・・・マトリクス駆動型のＥＣＢモード液晶素子 １０６・・・・・・ミラー １０７・・・・・・収差測定系 １０８・・・・・・コンピュータ １０９・・・・・・駆動回路 １１０・・・・・・メモリ ２０１・・・・・・偏光ビームスプリッタ ２０２・・・・・・マトリクス駆動型のＴＮモード液晶素子 ２０３・・・・・・レンズ ２０４・・・・・・ミラー ２０５・・・・・・レンズ ２０６・・・・・・マトリクス駆動型のＥＣＢモード液晶素子 ２０７・・・・・・マトリクス駆動型のＴＮモード液晶素子 ２０８・・・・・・レンズ ２０９・・・・・・ミラー ２１０・・・・・・レンズ ２１１・・・・・・マトリクス駆動型のＥＣＢモード液晶素子 ２１２・・・・・・偏光ビームスプリッタ 101 ... Matrix drive type TN mode liquid crystal element 102 ... Lens 103 ... Spatial filter 104 ... Lens 105 ... Matrix drive type ECB mode liquid crystal device 106 ··· Mirror 107 ··· Aberration measuring system 108 ··· Computer 109 ··· Drive circuit 110 ··· Memory 201 · · ...... Polarization beam splitter 202 ・ ・ ・ ・ ・ Matrix drive type TN mode liquid crystal element 203 ・ ・ ・ ・ ・ Lens 204 ・ ・ ・ ・ ・ Mirror 205 ・ ・ ・ ・ ・ Lens 206 ・ ・ ・・ ・ ・ Matrix drive type ECB mode liquid crystal element 207 ・ ・ ・ Matrix drive type TN mode liquid crystal element 208 ・ ・ ・ ・ ・ Lens 209 ・ ・ ・ ・ ・ Mirror 210 ・ ・ ・・ ・ ・ Lens 211 ・ ・ ・ ・ Matrix drive type ECB mode liquid crystal element 212 ・ ・ ・ ・ Polarizing beam splitter
Claims (3)
し、液晶素子と、前記液晶素子の駆動回路と、光波面の
位相分布を測定する手段と、前記光波面を測定する手段
により得られた信号を前記液晶素子の駆動回路へ帰還す
る回路を備えて成ることを特徴とする光学装置。1. A technique for correcting the amplitude and phase of a light wave front, which is obtained by a liquid crystal element, a drive circuit for the liquid crystal element, a means for measuring a phase distribution of the light wave front, and a means for measuring the light wave front. An optical device comprising a circuit for returning the generated signal to the drive circuit of the liquid crystal element.
子と、前記複数の液晶素子の駆動回路を備えて成ること
を特徴とする請求項１に記載の光学装置。2. The optical device according to claim 1, further comprising an amplitude modulation liquid crystal element, a phase modulation liquid crystal element, and a drive circuit for driving the plurality of liquid crystal elements.
の間にアフォーカル光学系を備え、前記振幅変調用液晶
素子と前記位相変調用液晶素子が前記アフォーカル光学
系において互いに共役な関係で配置されて成ることを特
徴とする請求項１ないし２に記載の光学装置。3. An afocal optical system is provided between the amplitude modulation liquid crystal element and the phase modulation liquid crystal element, and the amplitude modulation liquid crystal element and the phase modulation liquid crystal element are in a conjugate relationship with each other in the afocal optical system. The optical device according to claim 1 or 2, wherein the optical device is arranged in (1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22787091A JPH0566377A (en) | 1991-09-09 | 1991-09-09 | Optical device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22787091A JPH0566377A (en) | 1991-09-09 | 1991-09-09 | Optical device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0566377A true JPH0566377A (en) | 1993-03-19 |
Family
ID=16867644
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22787091A Pending JPH0566377A (en) | 1991-09-09 | 1991-09-09 | Optical device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0566377A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06181358A (en) * | 1992-10-06 | 1994-06-28 | Toshiba Corp | Laser control device |
| US6650476B1 (en) * | 1999-02-25 | 2003-11-18 | Lester Frank Ludwig | Image processing utilizing non-positive-definite transfer functions via fractional fourier transform |
| US7039252B2 (en) | 1999-02-25 | 2006-05-02 | Ludwig Lester F | Iterative approximation environments for modeling the evolution of an image propagating through a physical medium in restoration and other applications |
| US7054504B2 (en) | 1999-02-25 | 2006-05-30 | Ludwig Lester F | Relative optical path phase reconstruction in the correction of misfocused images using fractional powers of the fourier transform |
| WO2019031187A1 (en) * | 2017-08-07 | 2019-02-14 | ソニー株式会社 | Phase modulation device, illumination device, and projector |
-
1991
- 1991-09-09 JP JP22787091A patent/JPH0566377A/en active Pending
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06181358A (en) * | 1992-10-06 | 1994-06-28 | Toshiba Corp | Laser control device |
| US6650476B1 (en) * | 1999-02-25 | 2003-11-18 | Lester Frank Ludwig | Image processing utilizing non-positive-definite transfer functions via fractional fourier transform |
| US6972905B2 (en) | 1999-02-25 | 2005-12-06 | Ludwig Lester F | Non-positive-definite optical filtering from positive-definite transfer functions |
| US7039252B2 (en) | 1999-02-25 | 2006-05-02 | Ludwig Lester F | Iterative approximation environments for modeling the evolution of an image propagating through a physical medium in restoration and other applications |
| US7054504B2 (en) | 1999-02-25 | 2006-05-30 | Ludwig Lester F | Relative optical path phase reconstruction in the correction of misfocused images using fractional powers of the fourier transform |
| USRE42187E1 (en) * | 1999-02-25 | 2011-03-01 | Ludwig Lester F | Iterative approximation environments for modeling the evolution of an image propagating through a physical medium in restoration and other applications |
| WO2019031187A1 (en) * | 2017-08-07 | 2019-02-14 | ソニー株式会社 | Phase modulation device, illumination device, and projector |
| CN110998418A (en) * | 2017-08-07 | 2020-04-10 | 索尼公司 | Phase modulator, illumination system, and projector |
| JPWO2019031187A1 (en) * | 2017-08-07 | 2020-08-27 | ソニー株式会社 | Phase modulator, illumination device, and projector |
| US11258994B2 (en) | 2017-08-07 | 2022-02-22 | Sony Corporation | Phase modulator, lighting system, and projector |
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