WO2009041749A1

WO2009041749A1 - Image diffraction experimental device using raser beam

Info

Publication number: WO2009041749A1
Application number: PCT/KR2007/006025
Authority: WO
Inventors: Jin Gyu Kim; Youn Joong Kim; Jong Man Jeung; Eul Hyun Koo
Original assignee: Korea Basic Science Institute
Priority date: 2007-09-28
Filing date: 2007-11-27
Publication date: 2009-04-02
Also published as: KR20090032477A; KR100916528B1

Abstract

The present invention relates to an image diffraction experimental device using a laser beam, in that it includes a laser beam gun part portion (1), a sample supporting portion (2), an objective lens portion (3), an intermediate lens portion (4), a projector lens portion (5), a screen (6), a CCD (charge-coupled device) (7), a personal computer (8), and a fixing structures (9), so that it can be directly established and control each elements by the user so as to deal with the experimental. Accordingly, it can magnify various diffraction grating images and diffraction figures up to (44) magnifications maximally and obtain a resolution of about 5μm maximally, so that i can easily understand the mutual relation between the images and the diffraction figures on various samples and deeply comprehend the concept of the real space and reciprocal space, whereby being easily accessible to the principle and practical application of the TEM (transmission electron microscope).

Description

[Invention Title] IMAGE DIFFRACTION EXPERIMENTAL DEVICE USING RASER BEAM

[Technical Field]

The present invention relates to an image diffraction experimental device using a laser beam, and more particularly, to an image diffraction experimental device using a laser beam, in that it includes a light source portion for aligning the laser beam as a light source and an optical axis of the laser beam, a sample supporting portion, an objective lens portion, an intermediate lens portion, a projector lens portion, a CCD (charge-coupled device), a personal computer, and a fixing structures for vertically adjusting the lens, so that it can magnify various diffraction grating images and diffraction figures up to 44 magnifications maximally and obtain a resolution of about 5μm maximally. Accordingly, it can be directly established by the user and observe the formation of the images and diffraction figures through the lens, so that the concept of the real space and reciprocal space can be deeply comprehended, whereby being easily accessible to the principle and practical application of the TEM (transmission electron microscope).

[Background Art]

Generally, a TEM (transmission electron microscope) serves to receive the images of the samples and the diffraction signals by using an electronic beam and analyze the characteristics of the sample. Accordingly, it has been recognized that this TEM is indispensable to the development of nanotechnology materials, which is core research and development in the present or future.

In the ancient days of optical experiments, it had been conducted only through figures drawn based on supporting theories or simple experimental instruments using a light bulb or candlelight and so on by extension.

__ "I Recently, in order to improve the obscure experiments using these improper instruments, the optical experimental instruments have been commercially developed so as to directly check out through eyes of students and easily understand it (by Gu, Ul-Hyun in 1997).

However, in even those instruments, since it can understand only one phenomenon on the images and diffraction phenomenon, there is a limit that it cannot improve the power of understanding on the mutual relation between the images and diffraction phenomenon.

Moreover, in the conventional optical experimental instruments, it has been displayed an insufficiency of a phenomenon understanding on the reaction of the sample to the vertical beam shown in the optical microscope or electron microscope.

FIG. 1 is a conceptual view illustrating a TEM (transmission electron microscope).

As shown in Fig. 1, the TEM (transmission electron microscope), like the optical microscope, basically includes a focusing lens for focusing the electron beam as a light sources coming to the sample, an objective lens for adjusting the focus of the image on the sample, and a projector lens for magnifying the image. The optical microscope and the transmission electron microscope serve to magnify the image of the sample invisible to the naked eye and observe the magnified image in common.

In the meantime, the TEM (transmission electron microscope) can serve to magnify more images of the sample by using the electron beam having a wavelength shorter than a light in comparison with the optical microscope. Also, the TEM further includes a magnetic lens for freely adjusting the focus of each lens. Moreover, differently with the optical microscope capable of viewing only image, the TEM further includes an intermediate lens inserted between the objective lens and the projector lens, so that it can observe the diffraction and images on the samples (by Williams and Carter in 1995). However, since the TEM is unfamiliar with most researchers from the theory thereof to the analysis of the results, it is difficult of access and has difficulty in training advanced human resources. That is, although the theory of the TEM is almost identical with that of the optical microscope, it is difficult to understand the diffraction phenomenon generated internally by the reciprocal reaction between the sample and the electron beam and the theory of the image formation. [Disclosure] [Technical Problem]

Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide to an image diffraction experimental device using a laser beam in that only a essential lens portion is simply mounted thereon without forming the iris and lens coils, whereby easily understanding the analyzing principles of a TEM as well as an optical microscope.

Another object of the present invention is to provide to an image diffraction experimental device using a laser beam in that it can be directly established by the user and easily understand the mutual relation between the images on various samples and the diffraction figures through the control of each elements so as to solve the problem of the conventional optical experimental device, whereby being easily accessible to the principle and practical application of the TEM (transmission electron microscope).

Further another object of the present invention is to provide to an image diffraction experimental device using a laser beam capable of enhancing the power of understanding on the principal of the TEM as well as analyzing the sample of a simple system. [Technical Solution]

To achieve the above objects of the present invention, there is provided an image diffraction experimental device using a laser beam comprising: a laser beam gun portion for emitting a laser beam and aligning an optic axis of the laser beam and having an χ-axis beam adjusting tool, an y-axis beam adjusting tool, and a z-axis adjusting tool; a sample supporting portion for supporting a sample of transmitting the laser beam emitted by the laser beam gun portion and having a long guide groove for seating and guiding a sample holder formed at the center thereof in the direction of one side thereof and a screw moving pole having one end portion rotatively coupled to the sample holder and a screw portion, whereby the sample holder can be horizontally guided along the long guide groove according to a revolution of the screw moving pole in a forward or a backward direction; an objective lens portion having a fixing rack of a ring body shape for receiving a lens holder therein, an objective lens located at a center of the lens holder, and at least three minute adjusting screws penetrated through and coupled to a circumference of the lens holder so as to support the lens holder, whereby horizontally moving the lens holder to any position through the minute adjusting screws in order to align the objective lens; an intermediate lens portion for forming images and diffraction figures of the laser beam passing through the objective lens portion and adjusting a focus of the laser beam and having a fixing rack, a lens holder having an intermediate lens, and a guide groove for inserting the lens holder formed at one side of a circumference of the fixing rack; a projector lens portion identical with the objective lens in terms of constriction thereof so as to magnify the images of the laser beam passing through the intermediate lens portion; a screen for displaying the images and diffraction figures of the laser beam passing through the sample, the objective lens, the intermediate lens, and the projector lens thereon; a CCD for observing the images and diffraction figures with the naked eye, minutely adjusting a strength, magnification and focus of the laser beam, and transmitting the obtained data to a computer and having an external adjuster for manually operating it through an external terminal and performing an analysis of the sample; the computer for displaying the obtained data and storing the obtained data for analyzing the sample! and a fixing means for fixing and supporting the laser beam gun portion, the sample supporting portion, the objective lens portion, the intermediate lens portion, the projector lens portion, the screen, and the CCD (charge-coupled device).

Preferably, the fixing means comprises a plurality of fixing pieces having fixing screw axes corresponding to the sample supporting portion, the objective lens portion, the intermediate lens portion and the projector lens portion respectively, a long hole for guiding each fixing piece and moving each lens portion and the sample supporting portion vertically, and a knob coupled to the fixing screw axes of each fixing piece.

Preferably, the fixing means further comprises a tapeline for easily checking out a moving and measurement of the focus distance of the lens.

Accordingly, it can magnify various diffraction grating images and diffraction figures up to 44 magnifications maximally and obtain a resolution of about 5μm maximally, so that it can easily understand the mutual relation between the images and the diffraction figures on various samples and deeply comprehend the concept of the real space and reciprocal space, whereby being easily accessible to the principle and practical application of the TEM (transmission electron microscope) . [Advantageous Effects]

As described above, according to the image diffraction experimental device using a laser beam, the intermediate lens is newly inserted differently with the conventional optical experimental device, so that it can obtain the images of the samples and the diffraction figures at once.

Also, a medium is formed between each lens, so that it can follow and view the path of the beam passing through the sample, whereby easily understand the mutual reaction between the sample and the laser beam.

Moreover, the experimental materials can be stored in the CCD (charge-coupled device) and the computer and the stored materials can be analyzed through the professional programs, whereby understanding the principles of the crystal structure in the real space and reciprocal space, and magnifying various diffraction grating images and diffraction figures up to about 44 magnifications maximally and obtaining the resolution of about 5μm maximally so as to analyze the actual samples. [Description of Drawings]

The above as well as the other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a conceptual view illustrating a TEM (transmission electron microscope);

FIG. 2 is a conceptual view illustrating an image diffraction experimental device according to the present invention;

FIG. 3 illustrates a laser beam gun portion of an image diffraction experimental device according to the present invention;

FIG. 4 illustrates a sample holding portion of an image diffraction experimental device according to the present invention;

FIG. 5 illustrates an objective lens portion (a projector lens portion) of an image diffraction experimental device according to the present invention;

FIG. 6 illustrates an intermediate lens portion of an image diffraction experimental device according to the present invention! FIG. 7 illustrates a CCD of an image diffraction experimental device according to the present invention;

FIG. 8 illustrates fixing structures of an image diffraction experimental device according to the present invention;

FIG.9 is a planar sectional view illustrates fixing structures of an image diffraction experimental device according to the present invention;

FIG. 10 illustrates a path of the beam between lens;

FIG. 11 illustrates a diffraction beam passing through a projector lens according to the present invention;

FIG. 12 illustrates figures and types on each sample used in the present experiment; and

FIG. 13 illustrates images and diffraction figures on six samples observed by the image diffraction experimental device according to the present invention. [Best Mode]

A preferred embodiment of the invention will be described in detail below with reference to the accompanying drawings. FIG. 2 is a conceptual view illustrating an image diffraction experimental device according to the present invention. As shown in FIG.2, the image diffraction experimental device according to the present invention includes a laser beam gun portion 1, a sample supporting portion 2, an objective lens portion 3, an intermediate lens portion 4, a projector lens portion 5, a screen 6, a CCD (charge-coupled device) 7, a personal computer 8, and a fixing structures 9.

Since the laser beam using as a source of light of the laser beam gun portion 1 has excellent straightness and monochromaticity, it is unnecessary to insert a collimator and a monochromator therein. Preferably, the kind of the laser is a green laser (λ= 530 ~ 532 run, power = lOmw) having an excellent visualization, which is shorter than a red one in terms of a wavelength.

The important element of an optical microscope or a TEM is a laser beam alignment device. That is, as shown in FIG.3(a) and (b) , an adjusting tool 11 for aligning an χ-axis beam, an adjusting tool 12 for aligning an y-axis beam, and an adjusting tool 13 for aligning a z-axis beam are formed at the peripheral of the laser beam gun 10 so as to align the laser beam.

The laser beam of the laser beam gun 1 is emitted toward the center of the screen 6 and then, the incident laser beam is coincided with the reflected laser beam through the control of the three adjusting tools 11, 12, and 13 in order to align the laser beam. Finally, when the alignment of the laser beam is finished, by using a cover 14 shown in FIG. 3(c), it can prevent the alignment of the laser beam from being deviated on account of an external impact and so on. As shown in FIG.4, the sample supporting portion 2 of a cylinder shape includes a fixing piece 20 for easily fixing to the fixing structures 9 formed at one side of the circumference thereof, a long guide groove 21 for seating and guiding a sample holder 22 formed at the center thereof in the direction of one side, and a screw moving pole 23 having one end portion rotatively coupled to the sample holder 22 and a screw portion, whereby the sample holder can be horizontally guided along the long guide groove 21 according to the revolution of the screw moving pole 23 in the forward or backward direction.

Also, six samples can be seated on the sample holder 22 at one time. The size of the sample grid is about 3mm identically with the TEM. Accordingly, the sample holder 22 is mounted on the long guide groove 21 of the sample supporting portion 2 and then, various samples located on the sample holder 22 are minutely moved toward the center of the laser beam according to the adjustment of the screw moving pole 23, so that it can observe various diffraction figures or images. The objective lens portion 3 includes a fixing rack 30, a lens holder 31, a plurality of minute adjusting screws 32, and an objective lens 33.

The fixing rack 30 is in the form of a ring body shape so as to receive the lens holder 31 therein and another fixing piece 300 for easily fixing to the fixing structures 9 is formed at one side thereof.

The objective lens 33 is located at the center of the lens holder 31 and fixed to the lens holder 31 through a coupler 34, so that it can be mounted to the center of the lens holder 31 through the minute adjusting screws 32.

At least three minute adjusting screws 32 are penetrated through and coupled to the circumference of the lens holder 31, so that it can support the lens holder 31.

Accordingly, the lens holder 31 serves to align and fix the objective lens 33 to the selected position by horizontally moving it to any position through the minute adjusting screws 32, so that the laser beam passing through the samples can exactly reach the screen 6.

The objective lens 33 serves to adjust the image focus of the sample. The laser beam passing through the sample is reflected by the surface of the lens and the reflected beam is re-emitted by the sample supporting portion 2, so that it is finally imaged on the screen trough the lens. Accordingly, in order to remove the bad influence on the result image, it is preferred that an anti-reflected coating lens is utilized as the objective lens.

Here, the diameter and the focal distance of the objective lens 33 are 75mm and 50mm respectively. However, the present invention is not limited to the diameter and the focal distance thereof.

*As shown in FIG. 6, the intermediate lens portion 4 includes a fixing rack 40 of a circular shape, a fixing piece 400 for fixing to the fixing structures 9 formed at one side of the fixing rack 40, and a guide groove for inserting a lens holder 41 formed at one side of the circumference of the fixing rack 40.

The fixing rack 40 is physically moved between the objective lens portion 3 and the projector lens portion 5 and fixed to the desiring location through the fixing structures 9. Next to the fixing thereof, the lens holder 41 having an intermediate lens 42 is inserted into or removed from the guide groove, so that it can form various diffraction figures and images.

The intermediate lens 42 is used in only the TEM, differently with the optical microscope. Also, it can serve to selectively observe the diffraction figure and image on the sample.

Generally, since the lens used in the TEM is a magnetic lens, the amperage applied to the lens is adjusted, so that the focus of the electric beam passed through the sample can be adjusted in the objective lens, thereby forming the diffraction figure and image on the screen.

In the meantime, the lens used in the optical microscope or the present device is a general optical one. Accordingly, the focus distance can be fixed by simply inserting the lens holder 41 in the fixing rack 40.

The projector lens portion 5 is identical with the objective lens portion 3 in terms of constriction thereof. That is, the projector lens portion 5 includes a frame having a fixing piece, a lens holder, and minute adjusting screws.

Accordingly, the projector lens portion 5 serves to magnify the image.

The screen 6 is provided with a plane mirror for reflecting the laser beam.

As shown in FIG. 7, the CCD 7 for minutely adjusting a strength, magnification and focus etc. of the laser beam and transmitting the obtained data to a computer 8 includes an external adjuster for manually operating it through an external terminal formed at the side of the body of the computer 8. Conventionally, the laser beam passing through the sample runs through each lens, so that the image and diffraction figure can be formed on the screen 6. At this time, the image diffraction experimental device according to the present invention can not only observe the material formed on the screen 6, but also analyze the actual sample through the transmission method between the CCD 7 and the computer 8.

The computer 8 serves to display the materials obtained by the CCD 7 on a monitor by using an image capture program and store the displayed materials in the form of various formats so as to make a special study in future.

As shown in FIG. 8, the fixing structures 9 is strongly turned out so as to fix and support the laser beam gun portion 1, the sample supporting portion 2, the objective lens portion 3, the intermediate lens portion 4, the projector lens portion 5, the screen 6, and the CCD (charge-coupled device) 7. The fixing structures 9 includes a long hole 90 for guiding each fixing piece 20, 300, and 400 formed at the sample supporting portion 2, the objective lens portion 3, the intermediate lens portion 4 and the projector lens portion 5 and formed vertically at the middle portion thereof and a knob 92 coupled to fixing screw axes 91 formed at each fixing piece 20, 300, and 400, next to the appropriate adjustment of the sample supporting portion 2 and each lens up and down so as to exactly adjust the focus of the image and the diffraction figure.

Also, the fixing structures 9 further includes a tapeline 93 for easily checking out the measurement of the focus distance of the lens and the moving state of the lens formed at the side surface thereof. A process of image diffraction experiment using the image diffraction experimental device according to the present invention will be described below.

As described above, the object of the present invention is proved to the image diffraction experimental device capable of enhancing the power of understanding on the principal of the TEM as well as analyzing the sample of a simple system. In order to understand the diffraction phenomenon generated by passing the laser beam through the sample, it is very important that it observes the traveling path of the beam. For this reason, a little suspended solution is utilized as a medium, so that it can observe the path of the beam, as shown in FIG. 10.

FIG. 10(a) illustrates a path of the beam passing through the objective lens 33 located below the sample. So far, since the path of each diffraction beam is very short, it cannot observe the separated beams respectively until it observes near.

However, as shown in FIG. HXb), since the path of the beam passing through the intermediate lens 42 becomes properly longer, each of diffracted beams can be observed. Finally, the diffraction beams passing through the projector lens portion 5 can be more and more clearly observed as shown in FIG. 11.

Especially, as shown in FIG. 11 (c) and (d), strong diffraction beams can be minutely observed. That is, two or more beams are interfered through a constructive interference, thereby forming one beam. Accordingly, it can realize a realistic training.

In order to easily understand the diffraction phenomenon between the laser beam and the samples, the proper selection of the sample is important .

In the present experiments, simple samples as well as complicated samples can be inserted in stages, so that the diffraction figures can be observed according the images of the samples, thereby clearly understanding the concept of the real space and reciprocal space.

FIG. 12 illustrates figures and types on each sample used in the present experiment. The first sample of a single iris type can directly express the diffraction phenomenon and the second and third samples of one-dimensional grating type can illustrate the mutual relation between the real space and reciprocal space. Also, in the fourth through sixth samples of two-dimensional grating type, it can observe the diffraction figures of the reciprocal space on the regular arrangement of the real space of various forms, so that it can analyze and apply an atom arrangement on the samples of an actual three-dimensional structure.

FIG. 13 illustrates images and diffraction figures on six samples observed by the image diffraction experimental device according to the present invention.

Firstly, the amplification of the sample image can be calculated by the objective lens and the projector lens.

The entire amplification magnified through the objective lens and the projector lens can be briefly obtained from the following equation. Equation:

M = yO / yi = V / f

(Here, "M" is an amplification of the sample, "yO" and "yi" are a size of an actual sample and a size of an image displayed on a screen respectively, and "V" and "f" are the visibility distance and the focal distance respectively.)

Since the focal distance of the optical lens is fixed differently with the electron microscope, if the value of the total visibility distance or the size of the final image is found, the fixed amplification can be found.

Accordingly, in order to obtain the magnified images according to the above equation, the lens having a short focal distance is utilized or the length of the fixing structures 9 is lengthened so as to increase the visibility distance. However, the usage of the lens having a short focal distance such as the electron microscope can be more effective.

As shown in Fig. 13, the actual image of the detected sample (note FIG. 12 (a)) and the scale of the diffraction figure (note FIG. 12(b))are corrected based on the detected magnification and a FFT (Fast Fourier Transform) is performed from the image of the sample, so that it can calculate the reciprocal space (note FIG. 12 (c)).

Continuously, the calculated reciprocal space is compared with the diffraction figure and an IFFT (Inverse Fast Fourier Transform) is again performed from the data of the reciprocal space, thereby obtaining the real space (note FIG. 12 (d)). Finally, the obtained real space is compared with the image of the actual sample. Accordingly, it can be found that the detected actual material is coincided with the calculated materials in full. Where the image diffraction experimental device according to the present invention is utilized based on the analyzed data, it can be found that the resolution of about 5-15 μm can be obtained according to the kind of the sample.

As shown in FIG. 13, the diffraction figure of the first sample illustrates airy rings, which is a typical diffraction phenomenon generated by passing the laser beam through the iris of the sample.

*The diffraction figure of the second and third samples illustrate diffraction phenomenon using slits treated much in a general course of study. Actually, the second sample is larger than the third sample in terms of the width of the slits. However, the third sample is larger than the second sample in terms of the interval of the diffracted points within the diffraction figure. Accordingly, it can be found that the real space and the reciprocal space are in inverse proportion to each other in terms of the length thereof.

In the diffraction figure illustrating the reciprocal space shown in the fourth sample, as seen from the second and third samples, it can be predicted that rectangular grating figures having a different length can be formed in the actual sample in the real space. Similarly, in the fifth and sixth samples, the real space and the reciprocal space can be predicted from the diffraction figure and image thereof.

Accordingly, by using the image diffraction experimental device according to the present invention, it can observe the images and the diffraction figures of the samples at once and utilize as superior educational materials and aids in understanding the principles of the optical experiments and TEM and analyzing the actual samples. [Industrial Applicability]

The present invention relates to an image diffraction experimental device using a laser beam, in that it includes a light source portion for aligning the laser beam as a light source and an optical axis of the laser beam, a sample supporting portion, an objective lens portion, an intermediate lens portion, a projector lens portion, a CCD (charge-coupled device), a personal computer, and a fixing structures for vertically adjusting the lens, so that it can magnify various diffraction grating images and diffraction figures up to 44 magnifications maximally and obtain a resolution of about 5μm maximally.

While this invention has been described in connection with what are presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments and the drawings, but, on the contrary, it is intended to cover various modifications and variations within the spirit and scope of the appended claims.

Claims

[CLAIMS] [Claim 1]

An image diffraction experimental device using a laser beam comprising: a laser beam gun portion for emitting a laser beam and aligning an optic axis of the laser beam and having an χ-axis beam adjusting tool, an y-axis beam adjusting tool, and a z-axis adjusting tool; a sample supporting portion for supporting a sample of transmitting the laser beam emitted by the laser beam gun portion and having a long guide groove for seating and guiding a sample holder formed at the center thereof in the direction of one side thereof and a screw moving pole having one end portion rotatively coupled to the sample holder and a screw portion, whereby the sample holder can be horizontally guided along the long guide groove according to a revolution of the screw moving pole in a forward or a backward direction; an objective lens portion having a fixing rack of a ring body shape for receiving a lens holder therein, an objective lens located at a center of the lens holder, and at least three minute adjusting screws penetrated through and coupled to a circumference of the lens holder so as to support the lens holder, whereby horizontally moving the lens holder to any position through the minute adjusting screws in order to align the objective lens! an intermediate lens portion for forming images and diffraction figures of the laser beam passing through the objective lens portion and adjusting a focus of the laser beam and having a fixing rack, a lens holder having an intermediate lens, and a guide groove for inserting the lens holder formed at one side of a circumference of the fixing rack; a projector lens portion identical with the objective lens in terms of constriction thereof so as to magnify the images of the laser beam passing through the intermediate lens portion; a screen for displaying the images and diffraction figures of the laser beam passing through the sample, the objective lens, the intermediate lens, and the projector lens thereon; a CCD for observing the images and diffraction figures with the naked eye, minutely adjusting a strength, magnification and focus of the laser beam, and transmitting the obtained data to a computer and having an external adjuster for manually operating it through an external terminal and performing an analysis of the sample! the computer for displaying the obtained data and storing the obtained data for analyzing the sample; and a fixing means for fixing and supporting the laser beam gun portion, the sample supporting portion, the objective lens portion, the intermediate lens portion, the projector lens portion, the screen, and the CCD (charge-coupled device). [Claim 2]

An image diffraction experimental device using a laser beam as claimed in claim 1, wherein the fixing means comprises a plurality of fixing pieces having fixing screw axes corresponding to the sample supporting portion, the objective lens portion, the intermediate lens portion and the projector lens portion respectively, a long hole for guiding each fixing piece and moving each lens portion and the sample supporting portion vertically, and a knob coupled to the fixing screw axes of each fixing piece. [Claim 3]

An image diffraction experimental device using a laser beam as claimed in claim 2, wherein the fixing means further comprises a tapeline for easily checking out a moving and measurement of the focus distance of the lens.