JP2007021044A - Method of deforming deformable mirror, optical device, and observation device for ocular fundus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To compensate aberrations of an optical device including an observation device for ocular fundus by using a deformable mirror offsetting wavefront distortion of a luminous flux of a reflection face. <P>SOLUTION: The deformable mirror is equipped with a plurality of electrode parts and the thin film-shaped reflection face which is disposed counter to the electrodes and generates distortion by an electrostatic voltage applied to the electrode parts, measures the voltage applied to each electrode part when a desired shape of the reflection face is formed by detecting reflection of the reflection face, takes the applied voltage to each electrode part corresponding to the reference shape of the reflection face as one set to store the prescribed number of sets corresponding to the prescribed number of different shapes of the reflection face, deforms the reflection face into the desired shape by superposing the stored sets of the electrode part and the applied voltage, and compensates the aberration. Preferably, the reference shape of the reflection face is stored in relation to a prescribed dimensionality of Zernike polynomials. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a deformation method of a deformable mirror for correcting aberration of light irradiated to a subject, an optical apparatus using the deformable mirror, and a fundus oculi observation device.

  In a conventional optical apparatus, a deformable mirror (hereinafter abbreviated as a deformable mirror) is used to correct optical distortion of light irradiated on a subject (see, for example, Patent Document 1 and Patent Document 2).

  In a fundus oculi observation device or the like, the reflected light from the fundus includes aberrations because the eye optical system is incomplete, and a clear fundus image cannot be obtained. This optical distortion can be corrected by a deformable mirror (see, for example, Patent Document 3). This fundus oculi observation device irradiates a subject's eye (referred to as the subject's eye) with a light beam emitted from a photographing light source, and guides the reflected light beam reflected on the fundus as a photographing light to a recording means to cause the fundus of the subject's eye. An apparatus for recording an image.

  In general, as shown in FIGS. 17 and 18, the deformable mirror 300 is arranged in an indoor atmosphere (air), a thin film mirror (membrane) 301 stretched around a frame 302, and a predetermined thickness on the thin film mirror 301. The thin film mirror 301 is a flexible film body having a light reflecting surface as a surface, and the electrode 305 is a substrate formed of a flat substrate. A plurality (5 in this example, 305-1 to 305-5) are arranged on the upper surface of 304. In this example, a power source 306 capable of applying predetermined voltages V1 to V5 is connected to each of the electrodes 305-1 to 305-5. By applying a predetermined voltage to each electrode 305, the applied voltage V and the thin film mirror electrode are applied. The thin film mirror 301 at a portion facing the electrode 305 is pulled by an electrostatic force corresponding to the distance, and is deformed so as to generate a desired distortion. In the figure, reference numeral 307 denotes an interval holding member that holds an interval between the thin film mirror 301 and the substrate 304. As shown in FIG. 18, such a deformable mirror 300 is deformed into a desired shape when predetermined voltages V1 to V5 are applied to the electrodes 305-1 to 305-5.

JP 2004-247947 A JP-A-9-152505 JP-A-11-137522

  By the way, the conventional deformable mirror 300 described above includes a large number of electrode portions, and when the thin film mirror 301 is deformed into a predetermined shape, a predetermined voltage must be applied to each electrode portion. However, it is not easy to accurately apply a predetermined voltage to each electrode part, and setting the voltage to be applied to all the electrode parts is complicated and time-consuming, resulting in a decrease in work efficiency. It becomes.

  Therefore, in the present invention, in order to solve the above-described problem, the voltage applied to the plurality of electrode units can be stored in advance so as to obtain an appropriate output signal based on the output signal from the apparatus. It is an object of the present invention to provide an optical device and a fundus oculi observation device that can provide a working part, perform individual voltage correction in a short time, and increase work efficiency.

  The invention of claim 1 comprises a plurality of electrode portions and a thin film-like reflecting surface that is arranged to face these electrodes and that is distorted by an electrostatic voltage applied to the electrode portions. In the deformation method of the deformable mirror for correcting the reflection surface, the reflected light of the reflection surface is detected, the applied voltage to each electrode part when the desired reflection surface shape is formed is measured, and the reflection surface shape as a reference A predetermined number of sets corresponding to a predetermined different number of reflecting surface shapes is stored as a set of voltages applied to the respective electrode units corresponding to, and the stored sets of electrode units and applied voltages are superimposed. In this way, the deformable mirror is deformed by deforming the reflecting surface into a desired shape.

  According to a second aspect of the present invention, in the deformable mirror deformation method according to the first aspect, the reference reflecting surface shape of the reflecting surface is provided corresponding to an element of a predetermined dimension of the Zernike polynomial. In other words, according to the present invention, the set for designating the reflecting surface shape is such that the Zernike degree shape Z (n, m) has a predetermined V1 volt voltage on the first electrode, a V2 volt voltage on the second electrode, ... It is assumed that a voltage of Vi volts is applied to the i-th electrode and a set of the electrode number and the voltage value applied to the electrode is set. Accordingly, the reflecting surface is regularly deformed corresponding to the shape of each Zernike order, and an arbitrary reflecting surface shape can be obtained by superimposing these.

  The invention of claim 3 includes a plurality of electrode portions, and a thin film-like reflecting surface that is disposed to face these electrodes and that is distorted by an electrostatic voltage applied to the electrode portions, and is deformed into a predetermined shape. A variable shape mirror that corrects wavefront distortion of the light beam on the reflection surface and a predetermined voltage corresponding to a predetermined different number of reflection surface shapes, with one set of voltages applied to the electrode portions corresponding to the reference reflection surface shape. Is stored in the storage unit based on the aberration detection signal detected by the aberration detection unit and the aberration detection unit that detects the aberration of the light from the object reflected by the deformable mirror. And a calculation controller that compensates the aberration by selecting a set of the applied electrode part and the applied voltage, superimposing them, and applying a voltage to the electrode part to deform the reflecting surface. It is an optical device.

  According to a fourth aspect of the present invention, in the optical device according to the third aspect, the storage unit includes a reference reflecting surface shape of the reflecting surface corresponding to elements of a predetermined dimension of the Zernike polynomial. .

The invention of claim 5 is a fundus oculi observation device comprising the optical device of claims 3 and 4.

  According to the first aspect of the present invention, when the reflecting surface of the deformable mirror is deformed to have a desired shape for aberration compensation, the stored sets of applied voltages to the respective electrodes are superimposed and obtained. Since the voltage can be applied to each electrode based on the measured value, the reflecting surface of the deformable mirror can be easily deformed in a short time, and the work efficiency can be improved without performing trial and error operations when correcting the aberration. it can.

  According to the second aspect of the present invention, since the reference reflection surface shape of the reflection surface is provided corresponding to the order of the Zernike polynomial, the reference reflection surface shape can be hierarchically arranged and stored.

  According to the invention of claim 3, in the optical apparatus, when the reflecting surface of the deformable mirror is deformed to have a desired shape for aberration compensation, it is stored in correspondence with the aberration signal from the aberration detector. Since it is only necessary to superimpose a set of applied voltages to each electrode and apply a voltage to each electrode based on the obtained value, the reflecting surface of the deformable mirror can be easily deformed in a short time. Work efficiency can be increased.

  According to the invention of claim 4, since the reference reflecting surface shape of the reflecting surface is provided corresponding to the order of the Zernike polynomial, the reference reflecting surface shape is hierarchically arranged and stored in the storage unit. In addition to reducing the capacity of the storage unit, it is possible to increase work efficiency without performing trial and error operations to obtain a necessary reflecting surface shape.

  According to the invention of claim 5, it is possible to easily obtain a fundus image with a high resolution by compensating the aberration caused by the eyeball with the deformable mirror.

Embodiments of a deformable mirror deformation method according to the present invention will be described below. The deformable mirror targeted by this example is MEMS (Micro
This is a membrane-type deformable mirror (deformable mirror (abbreviated as DM)) manufactured by the Electro Mechanical Systems process, and corrects aberrations of the human eye in the fundus oculi observation device. The deformable mirror 10 includes a silicon membrane mirror portion 11 formed by processing an SOI wafer and 85 electrodes 12. The diameter of the silicon membrane was 12 mm, and the maximum displacement was 16 μm at a driving voltage of 180V.

  In this example, the model eye aberration measured by the Shack-Hartmann wavefront sensor is expanded into a Zernike polynomial, and the shape of the membrane is made variable so that the shape of the membrane cancels the eye aberration by using a voltage arrangement suitable for each term of the Zernike polynomial. Determine the drive voltage of the mirror. These voltage arrangements are experimentally determined in advance. In this example, the aberration of the model eye could be corrected to RMS 0.1 μm or less. In this example, the effective diameter of the deformable mirror is 7.5 mm, and the pupil diameter of the model eye is 8.5 mm.

  High-resolution fundus cameras are expected to produce beautiful images that allow human photoreceptors to be seen. By using such a camera, it becomes possible to photograph a fine obstacle such as a new blood vessel without performing fluorescence fundus photographing, and the physical burden on the patient is reduced. When taking a fundus picture, the resolution originally possessed by the fundus camera cannot be obtained due to the effect of human eye aberration. In order to solve this problem, adaptive optics that can correct eye aberrations has been studied. Research on adaptive optics not only in the field of vision science but also in the field of astronomy and laser communication has been conducted at various research institutes using deformable mirrors using MEMS technology. The deformable mirrors that have been researched and developed so far are generally classified into a segment array type deformable mirror and a membrane type deformable mirror. A segment array type deformable mirror made by surface micromachining has a relatively small displacement (several μm), but fine shape control is easy. On the other hand, a membrane-type deformable mirror made by bulk micromachining has an advantage of a large deformation amount (-10 μm or more), but it is difficult to accurately make a required mirror shape.

  Since the aberration of the human eye is relatively large (-10 μm), a high-resolution fundus camera requires a deformable mirror having a large aberration correction capability. Therefore, we developed a membrane-type deformable mirror and applied it to adaptive optics. A fast algorithm in an aberration correction system including a membrane-type deformable mirror is also required to obtain an accurate mirror shape.

  In the following, the process flow of the deformable mirror, the performance of the deformable mirror, the aberration correction method of the deformable mirror, and the aberration correction result using the adaptive optics system will be described.

  The schematic structure of the deformable mirror according to this example is shown in FIG. 1, and the appearance is shown in FIG. The deformable mirror 10 according to this example includes a silicon membrane mirror unit 11, a multilayer PCB substrate 14 on which 85 electrodes 12 are formed, and a spacer 13 that keeps a distance therebetween. Further, in order to reduce the warpage of the multilayer PCB substrate, a metal plate 17 is bonded to the back surface of the PCB, and this metal plate 17 functions as a mounting portion for the deformable mirror. The deformable mirror 10 is provided with a metal frame 15 and a glass window 16 to protect the device.

The deformable mirror according to this example was created by the following procedure. As shown in FIG. 3, a 400 μm thick handle layer of an SOI wafer (FIG. 2A) is formed by DRIE (Deep-Reactive).
Etching was performed in a circular shape with a diameter of 12 mm by Ion Etching (FIG. 3B). The 1 μm thick oxide layer was removed with hydrofluoric acid (FIG. 3C). Then, aluminum (200 nm) was deposited on a silicon membrane (thickness 6 μm) as a highly reflective mirror (90% at 633 nm) (FIG. 3D). The silicon membrane mirror was fixed on the PCB substrate through three spacers using an epoxy adhesive and a glass ball having a diameter of 50 μm. This glass ball precisely controls the distance between the mirror and the electrode. Furthermore, the silicon membrane and the GND of the multilayer PCB were electrically connected using a conductive adhesive.

  FIG. 4 shows the amount of displacement of the deformable mirror at the center of the membrane when the same voltage is applied to all 85 electrodes. A displacement of up to 16 μm is obtained at about 180V. The response time (rise, fall) is 10 ms or less (see Table 1 in FIG. 5).

  Hereinafter, determination of the aberration correction performance of the deformable mirror will be described. An outline of the mirror shape measurement method is shown in FIG. In this example, a predetermined voltage is applied to the electrode of the deformable mirror by the drive circuit, and the mirror shape is measured with a Fizeau interferometer. This drive circuit can apply up to 300V to each electrode. In order to create a certain mirror shape (for example, a (2, ± 2) th order shape of a Zernike polynomial), it is necessary to apply a voltage of about 300 V to the peripheral electrode. The first computer PC1 calculates the mirror surface shape and the Zernike coefficient of each order from the interference fringes detected by the CCD of the Fizeau interferometer. The second computer PC2 sets the voltage applied to the 85 electrodes of the deformable mirror.

  First, shapes up to the fourth order of each Zernike order were formed on the deformable mirror. The results are shown in FIG. The tilt component (that is, the first-order component of the Zernike polynomial) and the spherical component (the (2,0) component of the Zernike polynomial) are deleted from the mirror shape in FIG. 7 and from all the following aberration diagrams in this description. . This is because the fundus camera can correct these components with other optical systems. The effective diameter of the deformable mirror is 7.5 mm.

  As a result, for the Zernike degree shape Z (n, m), a predetermined voltage of V1 volts is applied to the first electrode, a voltage of V2 volts is applied to the second electrode, and a voltage of V85 volts is applied to the 85th electrode. Then, a set of electrode numbers and voltage values applied to the electrodes is obtained. Accordingly, the reflecting surface has a regular shape as shown in FIG. 7 corresponding to the shape of each Zernike order, and an arbitrary reflecting surface shape can be obtained by superimposing these.

Next, human eye aberration was actually measured with a wavefront analyzer (KR-9000PW, manufactured by Topcon Corporation), and the data was set as the target aberration. An example of human eye aberration is shown in FIG. A shape that can correct these aberrations (targets A, B, and C in FIG. 8) was made with a deformable mirror. When the aberration is corrected by adaptive optics, the shape of the deformable mirror must be opposite in phase to the target aberration and half the size. That is, the residual aberration amount is expressed by the equation (1).
Residual aberration amount = Target aberration amount + 2 (mirror shape) (1)

  As shown in FIG. 8, the target aberration of the human eye can be corrected by this deformable mirror. The residual aberration amount RMS is 0.1 μm or less.

  Next, a method for correcting aberration using the deformable mirror according to this example will be described. FIG. 9 shows a graph of the displacement amount of the deformable mirror at the center of the membrane and the square of the voltage applied to all the electrodes. The displacement is approximately proportional to the square of the voltage. This shows that the magnitude of the Zernike coefficient is proportional to the square of the voltage applied to all the electrodes of the deformable mirror. Therefore, several square voltage distributions were applied to the electrodes. The voltage is proportional to the square value of the voltage value when the Zernike order form shown in FIG. 7 is formed. The voltage Vx applied to each electrode of the deformable mirror is calculated as shown in Equation (2).

Vx ² = (dx / do) Vo ² .... (2)
Here, V ₀ is the voltage value applied in FIG. 7, d ₀ is the magnitude of the Zernike coefficient calculated in FIG. 7, and dx is the magnitude of the newly targeted Zernike coefficient.

  FIG. 10 shows a comparison between the target coefficient for the Zernike coefficient of Z (3, -1) and the actually created Zernike coefficient. Similar relationships were experimentally obtained with other Zernike coefficients. Although there is a proportional relationship between the two, the actual Zernike coefficient is always slightly larger than the target coefficient. This is because the displacement amount of the deformable mirror and the square of the voltage value are not strictly proportional, as shown in FIG. However, since the target and the result have a linear relationship, a Zernike coefficient value having an arbitrary size can be easily generated from an appropriate voltage array.

Furthermore, experimental results show that an arbitrary shape can be created in this deformable mirror by adding and applying an array of square voltage values to a plurality of Zernike coefficients. When the target shape is composed of Zernike components; A, B, and C, the square of the voltage array that creates Zernike coefficients A, B, and C as described above; {VA (n) ² }, {VB (n) ² } , {VC (n) ² } is calculated. Here, the voltage applied to the electrode number n is calculated as shown in Equation (3).
V (n) = sqrt (Vadd (n) ² -Vmin ² ) .... (3)
here,
Vadd (n) ² = VA (n) ² + VB (n) ² + VC
(n) ² .... (4)
further,
Vmin = min {Vadd (1), Vadd (2), ..., Vadd (85)} .... (5)
It is. The voltage Vmin reduces the superposition voltage value and suppresses the magnitude of the spherical component Z (2, 0) without significantly affecting other higher-order Zernike coefficients.
The mirror shape experimentally created by the voltage arrangement determined by the equations (3) to (5) and its Zernike coefficient were compared with the mirror shape obtained by calculation and its Zernike coefficient. The voltage arrangement of Z (2, -2), Z (3, -3), Z (4, -4) was used for the experiment. These mirror shapes and Zernike coefficients are as shown in FIGS. 11 (a), (b), and (c). The experimentally obtained mirror shape and Zernike coefficient are as shown in FIG. 9 (d), and the theoretically calculated (required) mirror shape and Zernike coefficient are as shown in FIG. 11 (e). Are almost consistent. Thus, it can be seen that the Zernike coefficient can be overlaid using equation (3).

  Next, a fundus oculi observation device using the deformable mirror according to this example will be described. In this example, the aberration correction of the model eye was performed. FIG. 12 shows a fundus oculi observation device according to this example. The fundus oculi observation device 100 is an adaptive optics system including a deformable mirror 10 and an aberration measurement device. The optical system of the fundus oculi observation device according to this example includes a deformable mirror 10, a Shack-Hartmann wavefront sensor 20, which is an aberration measuring device that measures aberration generated in an eye optical system such as a crystalline lens or cornea, and a beam propagation optical system 30. Become. In such an apparatus, since the aberration deteriorates the fundus image, a beautiful fundus image is obtained by correcting the aberration with the deformable mirror 10. In this example, a cylindrical lens 41 is attached to the model eye 40 to generate an aberration, and this aberration is compensated by the deformable mirror 10. A pattern of 5 μmL / S is arranged on the fundus of the model eye. The beam propagation optical system 30 includes beam splitters 31 and 34, a movable prism 32, a dichroic mirror 33, a laser diode 35, a high sensitivity CCD 36, and a super luminescent diode (SLD) 37.

  In this adaptive optics system, spherical aberration can be automatically corrected by adjusting the optical path length using the movable prism 32. In this example, the effective diameter of the deformable mirror 10 is 7.5 mm, and the pupil diameter of the model eye is 8.5 mm. The incident angle of the deformable mirror 10 is 15 degrees.

  The Shack-Hartmann wavefront sensor 20 is known and includes a Hartmann plate 21 (that is, a microlens array) and a CCD 22. The CCD 22 is disposed at the focal position of the microlens. The deformable mirror 10 and the Hartmann plate 21 are optically conjugate positions. An SLD 37 having a wavelength of 840 nm is used as a light source of the Shack-Hartmann wavefront sensor 20 in order to avoid unnecessary interference noise. The SLD 37, the fundus of the model eye 40, and the CCD 22 are in a conjugate position. A fundus image is obtained using an LD light source having a wavelength of 633 nm.

  The test results are shown in FIG. The voltage applied to the deformable mirror was determined by the method described above. The upper case shows no correction, and the lower case shows correction. As shown in FIG. 13, the generated aberration can be suppressed to a residual aberration smaller than 0.1 μm in RMS (root mean square value) by this system. After the aberration correction by the deformable mirror 10, the pattern is clearly resolved. This indicates that sufficient resolution can be obtained to capture photoreceptor cells of the fundus of about 3 μm.

  The experimental results with more complicated aberrations are shown in FIG. 14 along with the progress of aberration correction. As the progress, the RMS of the residual aberration and the aberration map at the number of corrections are shown. Further, all Zernike coefficients before and after aberration correction are shown in FIG. The residual aberration is well suppressed at the orders up to the fourth order after correction, but higher order aberrations remain. The final RMS was 0.13 μm. In this experiment, fifth-order and sixth-order aberrations are not considered. It is considered that the RMS can be made smaller than 0.1 μm by correcting the order. As described above, the aberration can be automatically corrected by a simple method.

  Finally, we experimented how much aberration can be corrected with this deformable mirror. In order to increase the amount of aberration, cylindrical lenses of various powers were set in front of the model eye. FIG. 16 shows an experimental result in a case where a total RMS generates an aberration amount of 3.9 μm with a 2-diopter cylindrical lens. The adaptive optics system using this deformable mirror can suppress such a large aberration to a residual aberration RMS of 0.093 μm. This aberration correction amount is much larger than that of a deformable mirror currently on the market.

  As described above, in this example, an 85-electrode membrane-type deformable mirror was manufactured. The membrane has a diameter of 12 mm and a maximum displacement of 16 μm at a driving voltage of 180V. The patent applicant can correct the aberration of the model eye by using an adaptive optics system simulating the deformable mirror and the fundus camera. In this embodiment, the effective diameter of the deformable mirror is 7.5 mm, and the pupil diameter of the model eye is 8.5 mm. The eye aberration measured by the Shack-Hartmann wavefront sensor is developed into a Zernike polynomial, and the driving voltage of the deformable mirror is determined in advance by an experimentally determined individual shape so that the membrane cancels the eye aberration. It is determined using a voltage array to create the form of each term of the Zernike polynomial. The aberration of the model eye was corrected to 0.1 μm or less. The adaptive optics system using a deformable mirror was able to correct a large aberration (RMS 3.9 μm) to a residual aberration of 0.1 μm or less.

  In the above embodiment, the fundus oculi observation device is shown as a device that uses a deformable mirror, but various devices such as a head-up display, an astronomical telescope, and a laser irradiation device can be used as a device that mounts the deformable mirror. Can be used for equipment.

It is sectional drawing which shows the structure of the variable shape mirror which concerns on the example of an embodiment. It is an external view of the deformable mirror according to the embodiment. It is a figure which shows the manufacturing method of the variable shape mirror which concerns on the example of embodiment. It is a graph which shows the relationship between the applied voltage to the deformable mirror which concerns on the embodiment, and the displacement of a mirror. It is a table | surface which shows the response speed of the variable shape mirror which concerns on the example of embodiment. It is a block diagram which shows the apparatus which measures the reflective surface shape of the variable shape mirror which concerns on the embodiment. It is a figure which shows the shape and Zernike polynomial component of the variable shape mirror which concerns on the example of an embodiment. It is a figure which shows the example of the aberration compensation of the human eye by the deformable mirror which concerns on the embodiment. It is a figure which shows the relationship between the square value of the voltage applied to the deformable mirror which concerns on the example of an embodiment, and the displacement amount of a mirror. It is the figure which compared the coefficient made into the target regarding the shape of the Zernike order in the variable shape mirror which concerns on the example of an embodiment, and the actually made Zernike coefficient. It is a figure which shows that a mirror shape can be controlled by superimposing a Zernike coefficient in the deformable mirror according to the embodiment. It is a figure which shows the optical system of the fundus observation apparatus which concerns on embodiment. It is a figure which shows the observation result by the fundus observation apparatus shown in FIG. It is a figure which shows the fundus observation result with the model eye concerning another example. It is a figure which shows a Zernike coefficient when compensation of FIG. 14 is performed. It is a figure which shows the fundus observation result with the model eye concerning another example. It is sectional drawing which shows the structure of the conventional variable shape mirror. It is sectional drawing which shows the state of an action | operation of the deformable mirror shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Deformable mirror 11 ... Silicon membrane mirror part 12 ... Electrode 13 ... Spacer 14 ... Multilayer PCB board 15 ... Metal frame 16 ... Glass window 17 ... Metal plate 20 ... Shack-Hartmann wavefront sensor 21 ... Hartmann plate 30 ... Beam propagation optical system 31 ... Beam splitter 32 ... Movable prism 33 ... Dichroic mirror 34 ... Beam splitter 35 ... Laser diode 37 ... Super luminescent diode (SLD)
40 ... Model eye 41 ... Cylindrical lens

Claims (5)

A variable-shape mirror that includes a plurality of electrode portions and a thin-film-like reflecting surface that is disposed to face these electrodes and that is distorted by an electrostatic voltage applied to the electrode portions, and corrects wavefront distortion of a light flux on the reflecting surface. In the deformation method,
Detecting the reflected light of the reflecting surface, and measuring the applied voltage to each electrode portion when forming a desired reflecting surface shape,
The voltage applied to each electrode portion corresponding to the reflective surface shape as one reference is set as one set, and a predetermined number of sets corresponding to a predetermined different number of reflective surface shapes is stored.
A method of deforming a deformable mirror, wherein the reflecting surface is deformed into a desired shape by superimposing a set of the stored electrode portion and applied voltage. 2. The deformable mirror deforming method according to claim 1, wherein a reference reflecting surface shape of the reflecting surface is provided corresponding to an element of a predetermined dimension of the Zernike polynomial. A plurality of electrode portions and a thin film-like reflecting surface that is disposed opposite to these electrodes and that is distorted by an electrostatic voltage applied to the electrode portions, and is deformed into a predetermined shape to reduce the wavefront distortion of the reflected surface light flux. A deformable mirror to be corrected,
A storage unit storing a predetermined number of sets corresponding to a predetermined different number of reflecting surface shapes, with a voltage applied to each electrode unit corresponding to a reference reflecting surface shape as one set,
An aberration detector for detecting the aberration of light from the object reflected by the deformable mirror;
Based on the aberration detection signal detected by the aberration detector, the electrode unit and the applied voltage stored in the storage unit are selected and superimposed, and the reflective surface is deformed by applying a voltage to the electrode unit. And an arithmetic control unit for compensating for the aberration. The optical device according to claim 4, wherein the storage unit includes a reference reflection surface shape of the reflection surface corresponding to an element of a predetermined dimension of the Zernike polynomial. A fundus oculi observation device comprising the optical device according to claim 3.