JP2821059B2 - Electron holography real-time phase measurement method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase measurement method and apparatus using electron beam holography, and more particularly, to a phase distribution or intensity of an object to be observed from a two-beam image hologram formed using a coherent electron beam. The present invention relates to a method and an apparatus for real-time phase measurement of electron-electron holography, in which a distribution is reproduced in real time and dynamic movement of a sample can be observed in real time.

[0002]

2. Description of the Related Art Electron beam holography, which has been devised to correct the aberration of an electron lens and improve the resolution of an electron microscope, has hitherto been used to capture an electron beam hologram using an electron beam and reconstruct the electron beam hologram using a laser beam. It consists of two processes. FIG. 7 is a schematic diagram of an electron optical system for imaging an electron beam hologram. The sample 2 is arranged on one side of the optical axis, and the plane electron wave 1 having high coherence is incident along the optical axis. The electron wave 1 is transmitted through the sample 2 and is divided into an object wave modulated by the sample 2 and a reference wave not transmitted through the sample 2,
The light is temporarily condensed by the electronic objective lens 3 and forms an image on the intermediate image plane 5. An electronic biprism 4 is disposed between the objective lens 3 and the image formation plane 5, and an object wave passing through one side of the central filament is formed. The reference wave passing through the other is bent so as to intersect with the optical axis, and is superposed on the image plane 5 to form an interference fringe.
The interference fringes are magnified by an electronic lens 6 and recorded on a photographic film 7 to form an image hologram 7.

In order to visualize the phase distribution of the object wave recorded on the hologram 7 created by the electron beam hologram creating system 8 having such an arrangement as contour fringes, the phase distribution is recorded on the photographic film as described above. The hologram 7 is irradiated with a laser beam, and a plane wave is superimposed on the reproduced object wave to form an interference microscope image.

[0004]

However, a method of once recording an electron beam hologram on a photographic film, optically reproducing the hologram, and observing the phase distribution by causing the reproduced object wave and plane wave to interfere with each other. According to the method described above, the process of recording a hologram on a photographic film and reproducing the hologram with a laser beam requires a great deal of time and effort.
Real-time observation is not possible. Furthermore, electron beam holograms generally have excessive carrier interference fringes,
Because it is difficult to directly observe the phase distribution of the sample by directly observing the modulation of the hologram interference fringes, it is easy to select the field of view for hologram photography in the case of a sample that does not involve a change in the intensity of an electromagnetic field or the like. There are also problems.

The present invention has been made in view of such a situation, and an object of the present invention is to reproduce an electron beam hologram as an optical interference microscope image in real time at the same time as capturing an image, to obtain a phase distribution or intensity of an object to be observed. An object of the present invention is to provide an electron beam holography real-time phase measurement method and apparatus capable of observing a distribution in real time.

[0006]

According to the present invention, there is provided an electron beam holography real-time phase measuring method, comprising: an electron beam hologram comprising an interference fringe between an electron beam reference wave and an electron beam object wave modulated by a sample. Is imaged by imaging means, and the imaged hologram is displayed on an electro-optical display element having a spatial intensity modulation function or a spatial phase modulation function,
The method is characterized in that a plane wave or a conjugate object wave is superimposed on an object wave reproduced by injecting coherent light into the electro-optical display element, and an interference microscope image is formed in real time.

In this case, a liquid crystal panel comprising a polarizing plate and a sandwich cell of twisted nematic liquid crystal can be used as an electro-optical display element having a spatial intensity modulation function. As the electro-optical display element, a liquid crystal panel in which each pixel is formed of a sandwich cell of a nematic liquid crystal having a homogeneous alignment can be used.

Further, the electron beam holography real-time phase measuring apparatus of the present invention is a means for forming an electron beam hologram comprising interference fringes between an electron beam reference wave and an electron beam object wave modulated by a sample. Imaging means for imaging an electron beam hologram; an electro-optical display element having a spatial intensity modulation function or a spatial phase modulation function for displaying the imaged hologram as an intensity image or a phase image; And an optical system for forming an interference microscope image in real time by superimposing a plane wave or a conjugate object wave on the object wave reproduced by entering coherent light into the element.

[0009] In this case, the phase distribution is doubled by applying two plane waves having a predetermined angle to the electro-optical display element and superimposing ± 1 diffracted waves from the displayed hologram on each other. It can also be configured to form an enhanced interference microscopic image, and a liquid crystal panel composed of a nematic liquid crystal sandwich cell in which each pixel is homogeneously oriented is used as an electro-optical display element. Incident on two plane waves at a predetermined angle,
It is also possible to compose an interference microscope image in which the ± higher-order diffracted waves from the displayed hologram are superimposed on each other and the phase distribution is enhanced to twice the order thereof. In particular, in the latter case, if the hologram imaged by the imaging means is subjected to non-linear processing and then displayed on the liquid crystal panel, the diffracted light can be concentrated on the higher-order terms.

Further, a second electro-optical display element having a spatial phase modulation function is provided on the Fourier transform plane of the reproduced wave from the electro-optical display element, and the aberration in the means for forming an electron beam hologram is reduced by this second element. The correction may be performed in real time by the two electro-optical display elements.

In any case, when the optical system is used to form an interference microscope by superimposing a plane wave or a conjugate object wave on the reproduced object wave, the phase difference between the two wavefronts must be between 0 and 2π. It is configured to interfere with the image plane of the object wave by changing to the steps, and from the intensity distribution of the interference fringes corresponding to each phase difference,
It is possible to determine the phase distribution of the object wavefront.

[0012]

According to the present invention, an electron beam hologram is picked up by an image pickup means, and the hologram can be rewritten in real time and displayed on an electro-optical display element which does not require fixing or development processing. The electron beam hologram picked up in step 2 is displayed as a video signal on this electro-optical display element every moment, and the hologram is immediately reproduced, so that the dynamic movement of the sample under the action of an electromagnetic field, heat, etc. Observation becomes possible. Further, since the equiphase interference fringes of the phase distribution of the sample can be obtained immediately, it is easy to observe the sample having no intensity distribution such as an electromagnetic field distributed in a vacuum.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The principle and an embodiment of a method and apparatus for real time phase measurement of electron beam holography according to the present invention will be described below with reference to the drawings. First, the basic principle of the present invention is that instead of recording an electron beam hologram on a photographic film, an electron beam hologram is imaged by an imaging means, and the hologram is not subjected to a developing or fixing process. Display on the display element, irradiate the displayed hologram with laser light to optically reproduce the recorded object wave, and superimpose a plane wave etc. on the reproduced wave front to form equiphase interference fringes and observe it It is to be.

Next, an apparatus for implementing this principle will be described with reference to the optical path diagram of FIG. 1. An electron beam hologram of the sample 2 is placed on the fluorescent screen 9 by the electron beam hologram forming system 8 as described in FIG. Formed. The hologram formed on the fluorescent plate 9 is imaged by the imaging device 10, and the video signal from the hologram is output and displayed on the liquid crystal panel 12 via the liquid crystal driver 11. Therefore, the hologram formed on the fluorescent screen 9 is displayed on the liquid crystal panel 12 in real time. This is the most important point in the present invention.

The liquid crystal panel 12 is composed of a large number of display pixels, and any of a liquid crystal panel that displays a hologram as an intensity image and a liquid crystal panel that displays a hologram as a phase image may be used. In order to display an intensity image, as each pixel, for example, a twisted nematic liquid crystal is subjected to a twisted orientation of nearly 90 °, and a light intensity modulation element configured by attaching polarizing plates on both sides is used, and a phase image is displayed. For example, an optical phase modulation element formed of a nematic liquid crystal sandwich cell in which each pixel has a holistic alignment (alignment such that a major axis of liquid crystal molecules is parallel to a glass substrate) is used.

FIG. 2 shows the structure of a twisted nematic liquid crystal sandwich cell, which utilizes the optical rotation of the twisted nematic liquid crystal. As shown in FIG. 2A, the liquid crystal is sealed between two glass substrates 52 coated with a transparent electrode 53, and the liquid crystal molecules 51 are applied to the liquid crystal by an alignment film 54 at an applied voltage of 0V. The long axis direction of the molecule 51 is parallel to the glass substrate 52, and the orientation is twisted by nearly 90 ° between the two glass substrates 52. In such a state, when the passing axes of the polarizer 56 and the analyzer 57 arranged on both sides are placed in parallel with each other, when the applied voltage 55 is 0 V, the linearly polarized incident light 58 is transmitted by the liquid crystal cell. Because the plane of polarization rotates 90 °,
The light cannot pass through the analyzer 57, and the emitted light becomes zero. On the other hand, as shown in FIG. 4B, when the applied voltage 55 is higher than the threshold value, the liquid crystal molecules 5 between the two glass substrates 52
In 1, the twisted orientation is released and the plane of polarization does not rotate, so that the incident light can pass through the analyzer 57 and the emitted light is in a bright state. By setting the applied voltage 55 to an intermediate value, the intensity of the emitted light can be adjusted, so that an intensity image can be displayed.

FIG. 3 shows a structure of a nematic liquid crystal sandwich cell of a homogeneous alignment. The liquid crystal is sealed between two glass substrates 62 coated with a transparent electrode 63, and the liquid crystal molecules 61 It is oriented without being twisted parallel to the glass substrate 62 by the orientation film 64. A nematic liquid crystal has the same refractive index anisotropy (birefringence) as a uniaxial optical crystal having an optical axis in the major axis direction of liquid crystal molecules. That is, the refractive index n _e of the light (extraordinary ray) in parallel to the vibration and the longitudinal direction of the liquid crystal molecules, a value different from the refractive index n _o of the long axis and the vertical vibrating light of the liquid crystal molecules (ordinary ray) have. Therefore, if the major axis direction of the liquid crystal molecules 61 is changed within the vibration plane of the incident light by the applied voltage 65,
The effective refractive index of the liquid crystal can be changed, and the incident light 66
Can be changed. FIG.
, The incident light 66 is incident such that the polarization direction is parallel to the long axis direction of the liquid crystal molecules 61. FIG (a) shows the state when no voltage is applied 65, the refractive index of the liquid crystal at this time becomes a value n _e for extraordinary light. On the other hand, as shown in FIG.
Is applied, the direction is changed from the liquid crystal molecules 61 at the center of the liquid crystal layer so that the major axis direction is along the electric field. Refractive index at this time becomes a value n _o for ordinary light. If the value of the applied voltage 65 is changed, the amount of the liquid crystal molecules 61 whose molecular axis rotates changes, and the effective refractive index value can be changed continuously, and a phase image can be displayed.

An optical system as shown in FIG. 1 is used to reproduce an object wave in real time from the amplitude or phase hologram displayed on the liquid crystal panel 12 and observe it as an interference image. That is, the light from the laser 13 whose frequency and intensity have been stabilized passes through the objective lens, the spatial filter,
After being made into a plane wave having a uniform wavefront by a collimator 14 composed of a collimator lens, the light enters a half mirror 15. A part of the plane wave that has entered the half mirror 15 is reflected and becomes a reference wave for phase measurement.
The light is reflected by the mirror 16 whose position is controlled by the (electrostrictive element) 24. The remaining part of the incident plane wave passes through the half mirror 15 and the liquid crystal panel 12 on which the hologram is displayed.
Is irradiated. Since the liquid crystal panel 12 is disposed on the front focal plane of the lens 17, the light transmitted through the liquid crystal panel 12 and the light diffracted by the hologram are transmitted to the lens 17.
Thereby, the light is once focused on the rear focal plane. A spatial filter 18 is arranged at that position, and only the reproduced wavefront is passed as it is. The object wave selected by the spatial filter 18 is
An image is formed on an imaging device 22 via a half mirror 21 by a lens 20 disposed at a position separated by a focal length from the spatial filter 18 via a mirror 19. At this time, the plane wave reflected by the mirror 16 is also superimposed on the object wave by the half mirror 21 to form equiphase interference fringes. Imaging device 22
Are displayed on the image display device 23 and observed as an interference microscope image. Further, the wavefront phase distribution and the amplitude distribution can be obtained by storing the data in an image memory (not shown) and analyzing the interference fringes using a computer. On this occasion,
In order to accurately determine the phase distribution of the wavefront, phase modulation interferometry is used (for example, “Introduction to Applied Optical Measurement” written by Toyohiko Yatakai, pp. 131-135 (August 30, 1988, published by Maruzen Co., Ltd.) )reference). To this end, the PZT 24 is controlled to slightly move the mirror 16 back and forth so that the phase change between the two wavefronts that interfere with each other becomes 0, π / 2, π, and 3π / 2. From the corresponding intensity distribution of the interference fringes, the phase distribution of the reproduced wavefront is accurately obtained. The obtained phase distribution is output and displayed on the image display device 23.

In order to obtain an interference microscope image, instead of causing the object wave and the plane wave to interfere with each other, ± 1st-order diffracted waves from the hologram displayed on the liquid crystal panel 12 or ± 2
It is also possible to cause the object waves of the higher and lower order + and-to interfere with each other and enhance the phase distribution to cause the interference. When the ± n-order diffracted waves interfere with each other, the phase distribution represented by the equiphase interference fringes becomes 2n times. FIG. 4 shows an example of an arrangement for this purpose. The light from the laser 13 whose frequency and intensity are stabilized is converted into a plane wave having a uniform wavefront by the collimator 14, and then the half mirror 25 is turned on.
Incident on. Of the light split by the half mirror 25, the reflected light passes through the mirror 26, and the transmitted light reaches the half mirror 28 through the mirror 27, where it is recombined. Are not parallel to each other, but are combined at an angle such that predetermined high or negative high-order diffracted lights from the hologram by these lights travel in the same optical axis direction. The two plane waves forming such an angle are incident on the liquid crystal panel 12, and the hologram displayed thereon forms a + n-order reproduced wavefront from one plane wave and a -n-order reproduced wavefront (conjugate wavefront) from the other plane wave. It is reproduced so as to proceed along the optical axis. Since the diffracted waves other than the + n-order or -n-th order and the zero-order light generated at this time are at an angle with respect to the optical axis, the lens 29 disposed at the focal length position behind the liquid crystal panel 12 focuses on the rear side. These lights are once condensed on the surface, and a spatial filter 30 that cuts light other than the light traveling along the optical axis is arranged at that position, and the reproduced wavefront (+
(nth order) and its conjugate wavefront (−nth order), and both wavefronts that have passed through the filter 30 are collimated again by the lens 31, and the two wavefronts are combined on the imaging device 22 arranged at a position conjugate with the liquid crystal panel 12. Cause interference. In this manner, an interference microscope image in which the phase distribution is enhanced can be obtained, and the phase measurement accuracy is improved by the enhancement.

When the phase distribution is emphasized by interfering the + n-order reproduced wavefront and the conjugated -n-order conjugate wavefront as shown in FIG. 4, the intensity (amplitude) of the liquid crystal panel 12 as shown in FIG. 3) When a hologram display is used, the obtained order is limited to approximately ± 1 order. However, when a phase hologram as shown in FIG. 3 is used, the obtained order is ± 1 order. The higher order is obtained. In this case, the phase image displayed on the liquid crystal panel 12 may be subjected to non-linear processing in order to strongly diffract the light into a higher specific order other than the ± 1st order. For this purpose, for example, a video signal may be passed through a non-linear filter before being input to the liquid crystal driver 11.

Incidentally, since the electron lenses 3 and 6 of the electron beam hologram forming system 8 have only convex lenses unlike optical lenses, aberration cannot be canceled by combining a convex lens and a concave lens. The image enlarged by the above becomes an image affected by the aberration of the electron lenses 3 and 6, the intensity distribution of the image does not accurately reflect the distribution of the sample, and the resolution is greatly limited. In order to correct this aberration, it has been proposed by the present inventors that a Fourier transform is applied to a reconstructed wave from an electron beam hologram, and a phase distribution conjugate with the aberration wavefront included in the reconstructed wave of the hologram is added on the Fourier transform plane. (Japanese Patent Application 3-
No. 340782). This method can be applied to the electron beam holography real-time phase measurement device of the present invention.

FIG. 5 shows an arrangement similar to that of FIG.
In this case, a configuration for correcting the aberration of the electron hologram forming system 8 is added. That is, the diffracted object wave from the liquid crystal panel 12 selected by the spatial filter 18 is passed through a phase display type liquid crystal panel II 32 arranged immediately after the spatial filter 18 as shown in FIG.
A correction function having a sign opposite to that of the aberration to be corrected is created by the computer 33 and output to the liquid crystal panel II32 via the liquid crystal driver 34, whereby the liquid crystal panel II3
2, the phase of each pixel is changed according to each control signal,
It functions as a desired aberration correction phase filter. In this manner, the aberration of the object wave transmitted through the liquid crystal panel II32 is corrected in real time, so that the phase distribution of the interference microscope image obtained by the imaging device 22 is also accurate. Also,
When observing a sample having a weak phase distribution, a phase difference of π / 2 or -π / 2 is generated at the center point of the Fourier spectrum of the reproduced wave in the liquid crystal cell II32, and the phase distribution of the object is changed by a phase contrast microscope image. Can be observed as

In FIGS. 1, 4 and 5, since the mirrors 16 and 27 moved by the PZT 24 for performing the phase modulation interferometry are single plane mirrors, any one of the PZTs 24 is used to obtain a phase change. If it is finely moved in any direction, not only the phase but also the optical path of the reflected light will be shifted, and interference fringes with different phase differences cannot be obtained under the same conditions, which is insufficient for accurate phase measurement. is there. Therefore, in order to improve such a point, for example, a corner cube prism 35 as shown in FIG. 6 is used. FIG. 6 shows a case where the present invention is applied to an arrangement in which phase enhancement is performed as shown in FIG. 4, but can also be applied to a case where interference with a plane wave occurs as shown in FIG. In FIG. 6, light from a laser 13 is converted into a plane wave by a collimator 14 and then split by a half mirror 36. Of the divided light, the transmitted light is reflected by the fixed mirror 37, and the reflected light returns to the half mirror 36, where it is reflected and becomes one plane wave incident on the liquid crystal panel 12. The reflected light in the divided light enters the corner cube prism 35, is reflected in the opposite direction, passes through the half mirror 36, and becomes the other plane wave incident on the liquid crystal panel 12. These two plane waves are similar to the case of FIG.
Two plane waves are formed at an angle to each other, and a + n-order reproduced wavefront from one plane wave and a -n-order reproduced wavefront (conjugate wavefront) from the other plane wave travel along the optical axis. By the way, in order to introduce a different phase difference between two interfering wavefronts, the PZT 24 mounted on the back surface of the corner cube prism 35 is driven.
Even if the corner cube prism 35 is moved by
Because of the characteristics of the corner cube prism 35, there is no change in the optical path of the reflected light, so that interference fringes having different phase differences can be obtained under the same conditions.

While the method and apparatus for measuring the real-time phase of electron beam holography according to the present invention have been described based on several embodiments, the present invention is not limited to these embodiments, and various modifications are possible. In addition, the electronically controllable phase image display element and the spatial phase filter are not limited to the homogeneously aligned nematic liquid crystal described with reference to FIG. 3 and can be realized by other liquid crystal elements.
It can also be realized by vacuum-depositing an electro-optic crystal and sandwiching it with electrodes of a desired pattern from both sides. The electronically controllable intensity image display device is not limited to the twisted nematic liquid crystal device of 90 ° orientation described with reference to FIG.
It can also be realized by other liquid crystal elements, electro-optical elements and the like.

[0025]

As is apparent from the above description, according to the electron beam holography real-time phase measuring method and apparatus of the present invention, an electron beam hologram is picked up by an image pickup means, and this hologram can be rewritten in real time. Since the image is displayed on the electro-optical display element which does not require fixing and development processing, the electron beam hologram imaged by the imaging means is displayed on the electro-optical display element as a video signal every moment, and the hologram is immediately reproduced. , It becomes possible to observe the dynamic movement of the sample under the action of an electromagnetic field or heat. Further, since the equiphase interference fringes of the phase distribution of the sample can be obtained immediately, it is easy to observe the sample having no intensity distribution such as an electromagnetic field distributed in a vacuum.

[Brief description of the drawings]

FIG. 1 is an optical path diagram of an apparatus for implementing the principle of the electron beam holography real-time phase measurement method of the present invention.

FIG. 2 is a diagram for explaining the structure and operation of a twisted nematic liquid crystal sandwich cell.

FIG. 3 is a diagram for explaining the structure and operation of a homogeneously aligned nematic liquid crystal sandwich cell.

FIG. 4 is an optical path diagram of a device according to another embodiment.

FIG. 5 is an optical path diagram of a device according to another embodiment.

FIG. 6 is an optical path diagram of a device according to still another embodiment.

FIG. 7 is a schematic configuration diagram of an electron beam hologram imaging device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Plane electron wave 2 ... Sample 3 ... Electronic objective lens 4 ... Electronic biprism 5 ... Intermediate image plane 6 ... Electron lens 8 ... Electron beam hologram creation system 9 ... Fluorescent plate 10 ... Imaging device 11 ... Liquid crystal driver 12 ... Liquid crystal panel 13 ... Laser 14 ... Collimator 15 ... Half mirror 16 ... Mirror 17 ... Lens 18 ... Spatial filter 19 ... Mirror 20 ... Lens 21 ... Half mirror 22 ... Imaging device 23 ... Image display device 24 ... PZT 25 ... Half mirror 26,27 ... Mirror 28 half mirror 29 lens 30 spatial filter 31 lens 32 liquid crystal panel II 33 computer 34 liquid crystal driver 35 corner cube prism 36 half mirror 37 fixed mirror

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Akira Tomura 2-19-5 Kaedaoka, Hatoyama-cho, Hiki-gun, Saitama (56) References JP-A-5-322839 (JP, A) JP-A-58-58 155636 (JP, A) Applied Physics Vol. 48, No. 11, published in July 1979 Akira Sotomura Tsuyoshi Matsuda, Junji Endo Recent advances in electron beam holography 1094-P. 1100 Applied Physics Vol.53 No.8 Published August 1, 1984 Akira Sotomura Extreme Measurement Using Electron Holography P. 664-P. 674 (58) Fields investigated (Int. Cl. ⁶ , DB name) G03H 5/00 G03H 1/22 H01J 37/26

Claims (10)

(57) [Claims] An imaging means for imaging an electron beam hologram comprising an interference fringe between an electron beam reference wave and an electron beam object wave modulated by a sample; Display on an electro-optical display element having a phase modulation function, superimpose a plane wave or conjugate object wave on the object wave reproduced by injecting coherent light into this electro-optical display element, and generate an interference microscope image in real time. An electron holography real-time phase measurement method characterized by forming. 2. The electronic device according to claim 1, wherein a liquid crystal panel comprising a polarizing plate and a sandwich cell of a twisted nematic liquid crystal is used as the electro-optical display element having a spatial intensity modulation function. Line holography real-time phase measurement. 3. The electron beam according to claim 1, wherein a liquid crystal panel in which each pixel is formed of a sandwich cell of a nematic liquid crystal having a homogeneous alignment is used as the electro-optical display element having a spatial phase modulation function. Holographic real-time phase measurement. 4. A means for creating an electron beam hologram comprising interference fringes between an electron beam reference wave and an electron beam object wave modulated by a sample; an imaging means for imaging the created electron beam hologram; An electro-optical display element having a spatial intensity modulation function or a spatial phase modulation function for displaying a hologram as an intensity image or a phase image, and an object wave reproduced by entering coherent light into the electro-optical display element And an optical system for forming an interference microscope image in real time by superimposing a plane wave or a conjugate object wave on the electron beam holography. 5. The electron beam holography real-time phase measuring apparatus according to claim 4, wherein the optical system makes two plane waves having a predetermined angle incident on the electro-optical display element, and outputs the plane wave from the displayed hologram. An electron holography real-time phase measurement apparatus characterized in that one diffraction wave is superimposed on each other to form an interference microscope image in which the phase distribution is doubled. 6. The electron beam holography real-time phase measuring apparatus according to claim 4, wherein each of said pixels uses a liquid crystal panel composed of a sandwich cell of a nematic liquid crystal of a homogeneous alignment as said electro-optical display element, and said optical system comprises:
Two plane waves forming a predetermined angle are incident on this liquid crystal panel, and the higher order diffracted waves of ± from the displayed hologram are superimposed on each other to form an interference microscope image in which the phase distribution is enhanced to twice its order. An electron holography real-time phase measuring apparatus characterized by having the following configuration. 7. An electron beam holography real-time phase measurement apparatus according to claim 6, wherein the hologram imaged by the imaging means is subjected to a non-linear processing and then displayed on the liquid crystal panel. An electron beam holography real-time phase measurement device characterized by the following. 8. The electron beam holography real-time phase measuring apparatus according to claim 4, wherein a spatial phase modulation function is provided on a Fourier transform surface of a reproduced wave from the electro-optical display element. A second electro-optical display element having an electron beam hologram, wherein the second electro-optical display element corrects aberrations in the means for creating the electron beam hologram in real time. Holographic real-time phase measurement device. 9. The electron beam holography real-time phase measurement apparatus according to claim 4, wherein a spatial phase modulation function is provided on a Fourier transform surface of a reproduced wave from the electro-optical display element. A second electro-optical display element having a center of the Fourier spectrum of the reproduced wave,
A real-time phase measurement of electron beam holography, wherein a phase difference of π / 2 or -π / 2 is given to convert a phase distribution of a weak phase object into an intensity distribution and visualize it as a phase microscope image. apparatus. 10. The electron beam holography real-time phase measuring apparatus according to claim 4, wherein the optical system superimposes a plane wave or a conjugate object wave on the reproduced object wave to perform an interference microscope. At the time of formation, the phase difference between the two wavefronts is changed in a plurality of steps between 0 and 2π so as to cause interference at the image plane of the object wave, and from the intensity distribution of interference fringes corresponding to each phase difference. An electron holography real-time phase measurement apparatus, wherein a phase distribution of an object wavefront is obtained.