JPH05323859A - Method and instrument for measuring actual time phase of electron beam holography - Google Patents

Abstract

PURPOSE:To enable the observation of the phase distribution or intensity distribution of an object to be observed in real time by reproducing an electron beam holorgram as an optical interference microscopic image in real time simultaneously with photographing. CONSTITUTION:The electron beam hologram consisting of the interference fringes of electron beam reference waves and the electron beam object waves modulated by a sample 2 is picked up by an image pickup means 10 and the hologram subjected to the image pickup is displayed on an electrooptical display element 12 having a spacial intensity modulation function or spacial phase modulation function. Plane waves or conjugate object waves are superposed on the object waves reproduced by making coherent light incident on this electrooptical display element 12, by which the interference microscopic image is formed in real time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase measuring 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 by using a coherent electron beam. The present invention relates to an electron electron holography real-time phase measurement method and apparatus capable of reproducing a distribution in real time and observing a dynamic movement of a sample in real time.

[0002]

2. Description of the Related Art Electron holography, which has been devised to correct the aberration of an electron lens and improve the resolution of an electron microscope, is conventionally used for photographing an electron beam hologram using an electron beam and reproducing the electron beam hologram by a laser beam. It consists of two processes. FIG. 7 shows 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 made incident along the optical axis. The electron wave 1 passes through the sample 2, and is divided into an object wave modulated by the sample 2 and a reference wave that does not pass through the sample 2,
An electron biprism 4 is arranged between the objective lens 3 and the image plane 5, and an object wave passing through one side of the filament at the center of the electron beam is focused by the electron objective lens 3 and forms an image on the intermediate image plane 5. , The reference wave passing through the other is bent so as to intersect the optical axis, and is superposed on the image plane 5 to form an interference fringe.
This interference fringe is magnified by the electronic lens 6 and recorded on the photographic film 7 to form the 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 stripes, it is recorded on the photographic film as described above. Generally, a method of irradiating the hologram 7 with a laser beam and superposing a plane wave on the reproduced object wave to form an interference microscope image is adopted.

[0004]

However, a method of observing the phase distribution by once recording the electron beam hologram on the photographic film, optically reproducing it, and causing the reproduced object wave and the plane wave to interfere with each other is observed. According to the method, recording a hologram on a photographic film and reproducing it with a laser beam requires a great deal of time and labor.
Real-time observation is impossible. In addition, since electron interference holograms generally have too many carrier interference fringes,
Since it is difficult to directly observe the phase distribution of the sample by directly observing the modulation of the hologram interference fringes, in the case of a sample that is not accompanied by intensity changes such as electromagnetic fields, it is easy to select a field of view for hologram imaging. There is also a problem.

The present invention has been made in view of such circumstances, and an object thereof is to reproduce an electron beam hologram as an optical interference microscope image in real time at the same time as photographing, and to obtain a phase distribution or intensity of an observation object. 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]

An electron beam holography real-time phase measuring method of the present invention which achieves the above object, is an electron beam hologram composed of interference fringes of an electron beam reference wave and an electron beam object wave modulated by a sample. Is imaged by an 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,
This is a method characterized in that an interference microscope image is formed in real time by superimposing a plane wave or a conjugate object wave on an object wave reproduced by making coherent light incident on the electro-optical display element.

In this case, a liquid crystal panel having a polarizing plate and a sandwich cell of twisted nematic liquid crystal in each pixel can be used as an electro-optical display element having a spatial intensity modulation function, and a spatial phase modulation function can be obtained. As the electro-optical display device, a liquid crystal panel in which each pixel is composed of a sandwich cell of homogeneously aligned nematic liquid crystal can be used.

Further, the electron beam holography real-time phase measuring apparatus of the present invention is provided with a means for producing an electron beam hologram composed of interference fringes of an electron beam reference wave and an electron beam object wave modulated by a sample. Image pickup means for picking up an electron beam hologram, an electro-optical display element having a spatial intensity modulation function or a spatial phase modulation function for displaying the picked-up hologram as an intensity image or a phase image, and this electro-optical display An optical system is provided which forms an interference microscope image in real time by superimposing a plane wave or a conjugate object wave on an object wave reproduced by making coherent light incident on the element.

In this case, in the optical system, two plane waves forming a predetermined angle are incident on the electro-optical display element, and ± 1 diffracted waves from the displayed hologram are superposed on each other to double the phase distribution. The liquid crystal panel may be configured to form an enhanced interference microscope image, and a liquid crystal panel in which each pixel is composed of a sandwich cell of homogeneously aligned nematic liquid crystal is used as an electro-optical display element, and the optical system is used as a liquid crystal panel. Inject two plane waves forming a predetermined angle to
It is also possible to superimpose ± higher-order diffracted waves from the displayed hologram on each other to form an interference microscope image in which the phase distribution is emphasized to twice the order. Especially in the latter case, when the hologram imaged by the image pickup means is subjected to the 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 surface of the reproduced wave from the electro-optical display element, and the aberration in the means for producing the electron beam hologram is suppressed by this second The second electro-optical display element may be configured to perform correction in real time.

In any case, when a plane wave or a conjugate object wave is superposed on a reproduced object wave in the optical system to form an interference microscope, a phase difference between both wavefronts is 0 to 2π. It is configured so that it is changed in steps to cause interference in the image plane of the object wave, and from the intensity distribution of the interference fringes corresponding to each phase difference,
It is possible to obtain the phase distribution of the object wavefront.

[0012]

In the present invention, the electron beam hologram is picked up by the image pickup means, and the hologram can be rewritten in real time and is displayed on the electro-optical display element which does not require fixing or developing processing. The electro-optical hologram imaged at is displayed as a video signal on this electro-optical display element every second, and the hologram is reproduced immediately, so that the dynamic movement of the sample when subjected to the action of an electromagnetic field or heat. Can be observed. Further, since the equiphase interference fringes of the phase distribution of the sample can be obtained immediately, it becomes easy to observe the sample that does not have the intensity distribution of the electromagnetic field distributed in the vacuum.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The principle and embodiments of the electron beam holography real-time phase measuring method and apparatus of 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, the electron beam hologram is picked up by an image pickup means, and the hologram is subjected to electro-optics such as a liquid crystal panel without undergoing a process of development and fixing. Observe by displaying on a display element, irradiating the displayed hologram with laser light to optically reproduce the recorded object wave, and superimposing a plane wave etc. on the reproduced wavefront to form equiphase interference fringes. Is to

Next, an apparatus for implementing this principle will be described with reference to the optical path diagram of FIG. 1. An electron beam hologram preparation system 8 as described in FIG. To form. The hologram formed on the fluorescent screen 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 hologram displaying an intensity image and a hologram displaying a phase image may be used. To display an intensity image, for example, a light intensity modulation element configured by twisting nematic liquid crystal in a twisted orientation of about 90 ° and polarizing plates attached to both sides is used as each pixel, and a phase image is displayed. For this, an optical phase modulation element is used in which each pixel is, for example, a sandwich cell of a nematic liquid crystal having a holodious orientation (orientation such that the long axes of liquid crystal molecules are parallel to the glass substrate).

FIG. 2 shows the structure of a twisted nematic liquid crystal sandwich cell, which utilizes the optical rotatory power of twisted nematic liquid crystals. As shown in FIG. 2A, the liquid crystal is enclosed between two glass substrates 52 coated with transparent electrodes 53, and the liquid crystal molecules 51 are aligned by the alignment film 54 when the applied voltage is 0V. The major axis direction of the molecule 51 is parallel to the glass substrate 52, and the two glass substrates 52 are twisted at an angle of about 90 °. In this state, when the pass axes of the polarizer 56 and the analyzer 57 arranged on both sides are placed parallel to each other, when the applied voltage 55 is 0 V, the linearly polarized incident light 58 is generated by this liquid crystal cell. Since the plane of polarization rotates 90 degrees,
It cannot pass through the analyzer 57, and the emitted light becomes 0. On the other hand, when the applied voltage 55 is larger than the threshold value, the liquid crystal molecules 5 between the two glass substrates 52 are, as shown in FIG.
In No. 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 the bright state. Since the intensity of the emitted light can be adjusted by setting the applied voltage 55 to an intermediate value, it is possible to display an intensity image.

FIG. 3 is a view showing the structure of a homogeneously aligned nematic liquid crystal sandwich cell, in which liquid crystal is sealed between two glass substrates 62 coated with transparent electrodes 63, and liquid crystal molecules 61 are The alignment film 64 is aligned in parallel with the glass substrate 62 without twisting. The nematic liquid crystal has a refractive index anisotropy (birefringence) similar to that of a uniaxial optical crystal having an optical axis in the long axis direction of liquid crystal molecules. That is, the refractive index n _e of light (extraordinary ray) vibrating parallel to the long axis direction of the liquid crystal molecule and the refractive index n _o of light (ordinary ray) vibrating perpendicular to the long axis direction of the liquid crystal molecule are different values. 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
The optical path length, that is, the phase can be changed. Figure 3
At, the incident light 66 is incident such that the polarization direction is parallel to the long axis direction of the liquid crystal molecules 61. The figure (a) has shown the mode when the voltage 65 is not applied, and the refractive index of the liquid crystal at this time becomes the value _ne with respect to extraordinary light. On the other hand, as shown in FIG.
When the voltage is applied, the liquid crystal molecules 61 at the center of the liquid crystal layer are turned so that their major axis directions are along the electric field. Refractive index at this time becomes a value n _o for ordinary light. When the value of the applied voltage 65 is changed, the amount of the liquid crystal molecules 61 whose molecular axis rotates is changed, the effective refractive index value can be continuously changed, and a phase image can be displayed.

By the way, in order 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, an optical system as shown in FIG. 1 is used. That is, the light from the laser 13 whose frequency and intensity are stabilized is generated by the objective lens, the spatial filter,
A collimator 14 formed of a collimator lens forms a plane wave having a uniform wavefront, and then enters a half mirror 15. A part of the plane wave incident on the half mirror 15 is reflected and becomes a reference wave for phase measurement. This reference plane wave is a PZT.
It is reflected by the mirror 16 whose position is controlled by the (electrostrictive element) 24. The rest of the incident plane wave passes through the half mirror 15 and the liquid crystal panel 12 on which the hologram is displayed.
Irradiate. Since the liquid crystal panel 12 is arranged 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 not reflected by the lens 17.
Thus, the light is once focused on the rear focal plane. The spatial filter 18 is arranged at that position to allow only the reproduced wavefront to pass therethrough. The object wave selected by the spatial filter 18 is
An image is formed on an image pickup device 22 via a half mirror 21 by a lens 20 arranged 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
The interference fringes detected in step 3 are displayed on the image display device 23 and observed as an interference microscope image. Alternatively, the phase distribution and the amplitude distribution of the wavefront can be obtained by storing in an image memory (not shown) and performing interference fringe analysis by a computer. On this occasion,
In order to accurately obtain the phase distribution of the wavefront, phase modulation interferometry is used (for example, Toyohiko Yatagai, "Introduction to Applied Optical Optical Measurement", pages 131-135 (August 30, 1988, published by Maruzen Co., Ltd.). )reference). For that purpose, the PZT 24 is controlled so that the mirror 16 is slightly moved back and forth so that the phase change between the two wavefronts that interfere with each other becomes 0, π / 2, π, 3π / 2, and each phase change The phase distribution of the reproduced wavefront can be accurately obtained from the intensity distribution of the corresponding interference fringes. The obtained phase distribution is output and displayed on the image display device 23.

By the way, 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 ± 2th order.
It is also possible to cause the + and − object waves of the second and higher order to interfere with each other and emphasize the phase distribution. When the ± n-order diffracted waves are interfered with each other, the phase distribution represented by the equiphase interference fringe becomes 2n times. FIG. 4 is an example of an arrangement for that 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.
Incident on. Of the light split by the half mirror 25, the reflected light passes through the mirror 26, and the transmitted light passes through the mirror 27 and reaches the half mirror 28, respectively, where they are combined again. Are not parallel to each other, but are combined at an angle such that predetermined + or-higher-order diffracted lights from the hologram by those lights travel in the same optical axis direction. Two plane waves forming an angle as described above are incident on the liquid crystal panel 12, and a hologram displayed on the plane wave causes a reproduction wavefront of + nth order from one plane wave and a reproduction wavefront of −nth order from another plane wave (conjugate wavefront). Reproduced so as to follow the optical axis. Since the diffracted waves other than the + n-th order or the −n-th order and the 0th-order light that are generated at this time form an angle with respect to the optical axis, the rear-side focus is generated by the lens 29 disposed at the position of the focal length after the liquid crystal panel 12. These lights are once collected on the surface, and a spatial filter 30 that cuts off the light other than the light traveling along the optical axis is arranged at that position, and the reproduction wavefront (+
(nth order) and its conjugate wavefront (-nth order) are passed through, and both wavefronts that have passed through the filter 30 are collimated again by the lens 31, and both wavefronts are displayed on the image pickup device 22 arranged at a position conjugate with the liquid crystal panel 12. Interfere. In this way, an interference microscope image in which the phase distribution is emphasized can be obtained, and the phase measurement accuracy is improved by the amount of the emphasis.

When the + nth-order reproduced wavefront and the conjugate -nth-order conjugated wavefront thereof are interfered with each other to emphasize the phase distribution as shown in FIG. 4, the liquid crystal panel 12 has an intensity (amplitude) as shown in FIG. ) If the hologram display is used, the obtained order is limited to approximately ± 1st order, but if the phase hologram display as shown in FIG. 3 is used, the obtained order is ± 1st order. It is not limited to, but higher-order ones can be obtained. In this case, in order to strongly diffract to a higher specific order other than ± 1st order, the phase image displayed on the liquid crystal panel 12 may be subjected to nonlinear processing. For that purpose, for example, a non-linear filter may be passed through before the video signal is input to the liquid crystal driver 11.

By the way, unlike the optical lens, the electron lenses 3 and 6 of the electron beam hologram forming system 8 have only convex lenses. Therefore, the aberration cannot be canceled by combining the convex lens and the concave lens, and the electron lenses 3 and 6 cannot be canceled. The image magnified in (2) becomes an image affected by the aberration of the electron lenses 3 and 6, and the intensity distribution of the image does not correctly reflect the distribution of the sample, and the resolution is greatly limited. In order to correct this aberration, it is proposed by the present inventor that the reproduction wave from the electron beam hologram is subjected to Fourier transform and a phase distribution conjugate with the aberration wavefront included in the reproduction wave of the hologram is added on the Fourier transform plane. Has been done (Japanese Patent Application No. 3-
340782). This method can be applied to the electron beam holography real-time phase measuring apparatus of the present invention.

FIG. 5 shows an arrangement similar to that of FIG.
In the case of this figure, a configuration for correcting the aberration of the electronic 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 the phase display type liquid crystal panel II 32 arranged immediately after the spatial filter 18 as shown in each pixel in FIG.
A correction function having a sign opposite to that of the aberration to be corrected is created by the computer 33 and is output to the liquid crystal panel II 32 via the liquid crystal driver 34, whereby the liquid crystal panel II 3
The phase of each pixel of 2 is changed according to each control signal,
It functions as a desired phase filter for aberration correction. In this way, 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 obtained by a phase difference microscope image. Can be observed as

By the way, in FIGS. 1, 4 and 5, since the mirrors 16 and 27 moved by the PZT 24 for implementing the phase modulation interferometry are single plane mirrors, the PZT 24 is used to obtain the phase change. If you move it slightly in that direction, not only the phase but also the optical path of the reflected light will shift, and you will not be able to obtain interference fringes with different phase differences 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. 6 is applied to the arrangement for performing the phase enhancement as shown in FIG. 4, but can be applied to the case where the plane wave is interfered as shown in FIG. In FIG. 6, the light from the laser 13 is converted into a plane wave by the collimator 14 and then split by the half mirror 36. Of the split 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 split 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 the same as in the case of FIG.
Two plane waves forming an angle with each other are formed, and one plane wave reproduces a + nth-order reproduction wavefront, and the other plane wave reproduces a −nth-order reproduction wavefront (conjugate wavefront) along the optical axis. By the way, in order to introduce a different phase difference between two interfering wavefronts, the PZT 24 attached to the back surface of the corner cube prism 35 is driven.
Even if the corner cube prism 35 is moved by
Due to the characteristics of the corner cube prism 35, the optical path of reflected light from the corner cube prism 35 is the same, so that interference fringes having different phase differences can be obtained under the same conditions.

The electron beam holography real-time phase measuring method and apparatus of the present invention have been described above based on some embodiments, but the present invention is not limited to these embodiments and various modifications can be made. Further, 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 from both sides with electrodes having a desired pattern. Further, the electronically controllable intensity image display element is not limited to the twisted nematic liquid crystal element of 90 ° orientation described with reference to FIG.
It can be realized by other liquid crystal element, electro-optical element, or 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, the electron beam hologram can be imaged by the image pickup means and the hologram can be rewritten in real time. Since it is displayed on the electro-optical display element that does not require fixing or development processing, the electron beam hologram imaged by the image pickup means is displayed on this electro-optical display element as a video signal every moment, and the hologram is immediately reproduced. By carrying out, it becomes possible to observe the dynamic movement of the sample when subjected to 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 becomes easy to observe the sample that does not have the intensity distribution of the electromagnetic field distributed in the vacuum.

[Brief description of drawings]

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

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

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

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

FIG. 5 is an optical path diagram of another embodiment of the device.

FIG. 6 is an optical path diagram of an apparatus 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 ... Planar electron wave 2 ... Sample 3 ... Electron objective lens 4 ... Electron 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 ... Calculator 34 ... Liquid crystal driver 35 ... Corner cube prism 36 ... Half mirror 37 ... Fixed mirror

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Ishizuka 14-48 Matsufudai, Higashimatsuyama City, Saitama Prefecture (72) Inventor Akira Tonomura 2-19-5 Kaedeoka, Hatoyama Town, Hiki-gun, Saitama Prefecture

Claims (10)

[Claims] 1. An electron beam hologram composed of interference fringes of an electron beam reference wave and an electron beam object wave modulated by a sample is imaged by an imaging means, and the imaged hologram is spatially intensity-modulated or spatially modulated. A plane wave or conjugate object wave is superposed on the object wave reproduced by displaying it on an electro-optical display element having a phase modulation function and injecting coherent light into this electro-optical display element, and an interference microscope image is obtained in real time. 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 twisted nematic liquid crystal is used for each pixel as the electro-optical display device having the spatial intensity modulation function. Line holography Real-time phase measurement method. 3. The electron beam according to claim 1, wherein each electro-optical display element having a spatial phase modulation function is a liquid crystal panel in which each pixel is composed of a sandwich cell of homogeneously aligned nematic liquid crystal. Holographic real-time phase measurement method. 4. A means for creating an electron beam hologram composed of interference fringes of 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, and an imaged image. 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 making coherent light incident on the electro-optical display element. An electron beam holography real-time phase measuring apparatus, comprising: an optical system that superimposes a plane wave or a conjugated object wave on the optical axis to form an interference microscope image in real time. 5. The electron beam holography real-time phase measuring apparatus according to claim 4, wherein the optical system makes two plane waves forming a predetermined angle incident on the electro-optical display element, and ± from the displayed hologram. An electron beam holography real-time phase measuring device, characterized in that it is configured to superimpose one diffracted wave 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 electro-optical display element uses a liquid crystal panel formed of a sandwich cell of homogeneous alignment nematic liquid crystal, and the optical system comprises:
Two plane waves forming a predetermined angle are incident on this liquid crystal panel, and ± high-order diffracted waves from the displayed hologram are superposed on each other to form an interference microscope image in which the phase distribution is emphasized to twice the order. An electron beam holography real-time phase measuring device, which is configured as described above. 7. An electron beam holography real-time phase measuring apparatus according to claim 6, wherein the hologram imaged by said image pickup means is subjected to nonlinear processing and then displayed on said liquid crystal panel. Electron holography real-time phase measurement device characterized by: 8. The electron beam holography real-time phase measuring device 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. An electron beam having a second electro-optical display element which is provided, and is configured to correct the aberration in the means for producing the electron beam hologram in real time by the second electro-optical display element. Holographic real-time phase measurement device. 9. 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. The second electro-optical display element having is provided, and at the center of the Fourier spectrum of the reproduced wave,
Electron holography real-time phase measurement characterized by giving a phase difference of π / 2 or −π / 2 to convert the 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 form an interference microscope. At the time of formation, the phase difference between both wavefronts is changed in multiple steps between 0 and 2π so as to cause interference in the image plane of the object wave. From the intensity distribution of the interference fringes corresponding to each phase difference, An electron beam holography real-time phase measuring apparatus characterized in that a phase distribution of an object wavefront is obtained.