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Showing papers on "Zone plate published in 1982"


Journal ArticleDOI
Yuzo Ono1, Nobuo Nishida1
TL;DR: A remarkable aberration correction effect for this hologram generation method is demonstrated for over 50-cm scan length, and a generalized holographic zone plate is proposed.
Abstract: Aberration properties in holographic zone plates for use in laser scanners are investigated. A generalized holographic zone plate is proposed. To generate the zone plate hologram, holographic optical product operations between plural coherent spherical waves, are applied. When spherical waves, N in number, are applied, aberration can be corrected in a scan length magnification equal to or less than N2. Experimentally, a remarkable aberration correction effect for this hologram generation method is demonstrated for over 50-cm scan length. The configuration and features are described for the developed point-of-sale (POS) scanner employing generalized zone plate holograms.

24 citations


Journal ArticleDOI
TL;DR: In this paper, the diffraction wave field and irradiance distribution for the case of Fresnel diffraction of a square zone plate were studied, and the authors showed that the irradiance distributions of the diffracted wave field were similar to those of the irradiated wave field.
Abstract: Studies the diffraction wave field and the irradiance distribution for the case of Fresnel diffraction of a square zone plate.

24 citations


Proceedings ArticleDOI
24 Mar 1982
TL;DR: In this article, the intensity distribution of a zone plate with 50 or fewer open zones was calculated and the wavelength bandpass and allowable off-axistilt for zone plates were calculated and concluded that they should produce an intense nearly diffractionlimited spot when used with suitably monochromatized synchrotron radiation.
Abstract: One method for fabricating high resolution (%.lpm) Fresnel zone plates suitable forfocusing ultrasoft (',3nm) x -rays is electron beam lithography. Present technology limitsthe device size to about 100pm. For a scanning microscope we need to produce a small focalspot free of background. This requires a central stop on the zone plate as well as acollimator to eliminate the zeroth order radiation. The apodized region is now a signifi-cant fraction of the zone plate area and the intensity in the focal plane is no longer theAiry pattern of an ideal amplitude zone plate. We have calculated the intensity distribu-tions of some feasible zone plates with 50 or fewer open zones. The results indicate thatan acceptably small fraction of the first order radiation is shifted to the higher order lobes. In addition, we have calculated the wavelength bandpass and allowable off -axistilt for zone plates and conclude that they should produce an intense nearly diffractionlimited spot when used with suitably monochromatized synchrotron radiation.IntroductionThe Fresnel zone plate is the only optical element which has thus far demonstratedsubmicron resolution with ultrasoft X- rays.(1) We are building a scanning transmissionX -ray microscope(2)which will use such a zone plate to form a submicron spot through whicha biological specimen will be mechanically scanned. For unstained wet thick specimensthe resolution may turn out to be more limited by the radiation damage than by opticalconsiderations.(3) With no post- specimen optics and efficient electronic detection ofthe transmitted radiation, the damage to the specimen is minimized.Zone plate requirementsSome of the requirements for our zone plate are shown below:Requirementresolution ti 100nmhigh bandpassgood signal :noisesmall sizePurposesurpass opticalresolutionmaximize flux frommonochromatorincrease contrastreduce scan timecompatibility with ebeam fabricationImplementationfinest zone ti 80nmfew zonesapodized zone platewith collimatorshort focal lengthThe requirement for a small overall size is a consequence of the decision to use thetechnology of electron beam lithography to make the zone plate.(4) Although finer linesand more complicated patterns than we require have been written with e beam microfabricators,our requirements on precise placing of the zones will certainly test the optics and stabil-ity of the electron column. If the finest outer zone is 70nm wide, than the average errorin the placement of this zone can not be much more than 20nm before the radiation will nolonger interfere constructively. A small pattern can also be written quickly so thatdrift is less of a problem. The final pattern should be metallized on a thin substrate;about 100nm of gold in the opaque zones provides sufficient contrast for 3nm radiation.We are hopeful that a zoneplate with overall diameter of about 50 -100pm can be made usinge beam lithography.This small size does not exact much of a penalty in light gathering ability. If thediameter of the zone plate is D, the width of the outermost zone (Sr, then at wavelength Xthe focal length is approximately given by

16 citations


Patent
21 Jun 1982
TL;DR: In this paper, the authors describe methods and apparatus for engraving an image or pattern on the surface of a workpiece by varying the output of the laser beam in accordance with stored image defining signals to produce cells of uniform or different size and shape while scanning the workpiece surface.
Abstract: The laser beam is passed through diffraction means (15), which may be of any suitable form such as a diffraction grating, zone plate or diffraction aperture or a beam shaping mirror, and is then focussed onto the surface of the workpiece in the form of a diffraction pattern. In addition, the workpiece may be moved relative to the laser beam during engraving while praferably also varying the intensity (pulse- shape) of the laser beam to produce the cells of different size and configuration. The disclosure also describes methods and apparatus for engraving an image or pattern on the surface of the workpiece by varying the output of the laser beam in accordance with stored image defining signals to produce cells of uniform or different size and shape while scanning the workpiece surface.

14 citations


Proceedings ArticleDOI
24 Mar 1982
TL;DR: An X-ray microscope with a zone plate linear monochromator is described in this article, and a new micro zone plate for this microscope with one hundred zones was made.
Abstract: An X-ray microscope with a zone plate linear monochromator is described. A new micro zone plate for this microscope with one hundred zones was made. X-ray microscopy with synchrotron radiation has shown that a resolution in the 50 nm range has been achieved.© (1982) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

13 citations


Journal ArticleDOI
TL;DR: The diffraction efficiency, bandpass, and spurious beam rejection are studied for the holographic cascade lens that consists of a diffraction grating in contact with an off-axis zone plate.
Abstract: The diffraction efficiency, bandpass, and spurious beam rejection are studied for the holographic cascade lens that consists of a diffraction grating in contact with an off-axis zone plate An analysis is presented for the bandpass of the volume diffraction grating, including the effects of grain polarizability

12 citations


Journal ArticleDOI
TL;DR: A dichromated gelatin off-axis Fresnel zone plate (OFZP) was designed, fabricated, and used in a new type of interferometer for optical metrology, showing the successful application for an interferometric test of an f/6, 200-mm diam parabolic mirror.
Abstract: A dichromated gelatin off-axis Fresnel zone plate (OFZP) was designed, fabricated, and used in a new type of interferometer for optical metrology. This single hologram optical element combines the functions of a beam splitter, beam diverger, and aberrated null lens. Data presented show the successful application for an interferometric test of an f/6, 200-mm diam parabolic mirror.

11 citations


Patent
29 Dec 1982

8 citations


Patent
15 Sep 1982
TL;DR: In this paper, an apparatus for performing an incoherent optical Fourier transform is presented, which includes a source of incoherent light, means for generating and phase modulating a first zone plate, a second zone plate and means for filtering the output signal.
Abstract: An apparatus for performing an incoherent optical Fourier transform inclu a source of incoherent light, means for generating and phase modulating a first zone plate, a second zone plate, means for detecting incoherent light processed by the apparatus, and means for filtering the output signal, thereby discriminating between the Fourier transform signal and background constant or bias signals. A method for performing incoherent optical Fourier transform is also disclosed.

6 citations


Patent
21 Apr 1982
TL;DR: In this paper, fine alignment of mask and wafer using Fresnel zone plates is achieved by focussing light on the wafer by using a zone plate in the mask.
Abstract: Fine alignment of mask (12) and wafer (13), using Fresnel zone plates is achieved by focussing light on the wafer using a zone plate in the mask. Light diffracted from a zone plate on the wafer is received by a sensor (14). The received light is coded (analog or digital) to indicate alignment. For analog coding the wafer zone plate diffracts light to the sensor from an area of the wafer zone plate which is indicative of alignment. For digital coding the wafer plate is digitally encoded as a function of alignment to similarly code the diffracted light.

4 citations


Proceedings ArticleDOI
24 Mar 1982
TL;DR: In this paper, the authors describe a system for a scanning X-ray microscope with a resolution of 10 to 50 nm, which is under con-struction for a resolution between 10 and 50 nm.
Abstract: Some details of the scanning X -ray microscope are described. The system is under con-struction for a resolution of 10 to 50 nm.The necessity to build a scanning X -ray microscope results from the advantageously re-duced radiation dose of such a system compared with an imaging X -ray microscope.In an imaging X -ray microscope the X -rays first enter the object and then pass themagnifying micro zone plate, which has usually a diffraction efficiency of less thanten percent. Thus, more radiation passes the object than is diffracted into the image. Inan X -ray scanning microscope the X -rays first pass the micro zone plate. Only the X -rays,which are diffracted into the scan spot, enter the object and they all contribute to theimage. Also the detective quantum efficiency of the counter is much higher than of aphotographic plate.Secondly, the object can be examined in real time work using the potentiality ofelectronic signal processing to record and analyse the resulting micrographs.

Journal ArticleDOI
TL;DR: In this article, a new method was developed for making micro-fresnel zone plates used in the coded imaging of x rays and α particles produced from laser fusion target implosions.
Abstract: A new method has been developed for making micro‐Fresnel zone plates used in the coded imaging of x rays and α particles produced from laser fusion target implosions. The method allows the fabrication of numerous plating molds from a single master mold, which is particularly useful in α‐particle imaging since each target shot requires a new zone plate. A master mold was made in polyimide using reactive ion etching, and a number of silicone rubber replicas were made of the mold. Each replica was then used to produce a number of photoresist final molds into which gold was electroplated. This microfabrication technique has produced high quality 10‐μm‐thick zone plates having 100 zones and a 5‐μm‐wide outer zone.

Book ChapterDOI
01 Jan 1982
TL;DR: In this paper, it was shown that elastic wave generation and propagation inside the piezoelectric plate cause the acoustic field pattern directly in front of the plate to differ from the electrode pattern.
Abstract: Ultrasonic imaging transducers have been proposed in which a piezoelectric plate is used in conjunction with a Fresnel Zone Plate (FZP) to produce a focused beam of ultrasound. Focusing is achieved with these devices by activating the piezoelectric plate with an electrode pattern in the shape of an FZP. The focal plane distribution of these transducers cannot, in general, be predicted by diffraction theory alone. This is because the acoustic field pattern in front of the transducer is not an exact replica of the FZP electrode pattern. In this paper we show that elastic wave generation and propagation inside the piezoelectric plate cause the acoustic field pattern directly in front of the plate to differ from the electrode pattern. These effects are called mechanical aberrations. We show that mechanical aberrations cause the focal plane distribution to be broader than that predicted by diffraction theory. The effects on resolution of material properties and other device parameters are discussed. Experimental results are also presented.

Proceedings ArticleDOI
01 Nov 1982
TL;DR: In this article, the authors used a linear spatial piezo-electric model to construct a spatial transfer function for the piezoelectric plate and showed that elastic-wave generation and propagation inside the plate cause the acoustic field pattern just in front of the transducers to differ substantially from the electrode pattern.
Abstract: Piezoelectric transducers with an electrode pattern in the form of a Fresnel zone plate (FZP) on the air side and a full, planar electrode on the water side have been used in many acoustical imaging systems to focus the acoustic beam. The goal is to get an acoustic pressure pattern in the shape of an FZP. The acoustic pressure pattern, however, is never an exact replica of the FZP electrode pattern because of mechanical aberrations introduced by the piezo-electric plate. In a previous paper we derived the focal-plane acoustic field distribution of such a transducer. The distribution just in front of the transducer, however, was not given in that paper. In this paper we use a linear spatial piezo-electric model to construct a spatial transfer function for the piezoelectric plate. We show that elastic-wave generation and propagation inside the piezoelectric plate cause the acoustic field pattern just in front of the transducer to differ substantially from the electrode pattern. A plot of amplitude versus position on the piezoelectric plate shows that the sharp edges associated with the electrode pattern are severely rounded off by these effects and the amplitude is greatly reduced in the region of the outer zones. The aberrations also cause a vari-ation with the position of the phase of the out-put field.© (1982) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Patent
22 Apr 1982
TL;DR: In this paper, a linear Fresnel zone plate is composed of optical waveguides 11, 12 of electrooptic crystal having the (c) axis in a direction 29, and at the no-waveguide part of the Fresnel plate, electrodes 21, 22 having lengths l 1, l 2 proportional to the waveguide width are arranged So that adjacent electrodes have opposite phases, voltages are applied to the electrodes, thereby modulating the intensity of focusing light.
Abstract: PURPOSE:To achieve focusing and optical modulation simultaneously by forming a linear Fresnel zone plate by using thin-film optical waveguides of electrooptic crystal CONSTITUTION:A linear Fresnel zone plate is composed of optical waveguides 11, 12- of electrooptic crystal having the (c) axis in a direction 29, and at the no- waveguide part of the Fresnel zone plate, electrodes 21, 22- having lengths l1, l2- proportional to the waveguide width are arranged So that adjacent electrodes have the opposite phases, voltages are applied to the electrodes, thereby modulating the intensity of focusing light

Patent
27 Aug 1982
TL;DR: In this article, a fast and light-weight optical scanner is obtained by arranging a pair of comb line electrodes of a one-dimensional Fresnel zone plate in a thin film optical wave guide path.
Abstract: PURPOSE:To obtain an optical scanner which scans in a high speed with a low applied voltage and does not require a condenser lens, by arranging a pair of comb line electrodes of a one-dimensional Fresnel zone plate in a thin film optical wave guide path. CONSTITUTION:A one-dimensional Fresnel zone plate due to stripe thin film optical wave guide paths 41A... and 41B... different in width such as odd zones consisting of the electrooptic crystal of LiNbO3 or the like is formed on a substrate 40, and a pair of comb line electrodes 45 and 46 of the same length is arranged near boundaries of wave guide paths 41A... and 41B.... When a low voltage V is applied to these electrodes 45 and 46, a phase thetam induced by the electrooptic effect of the m-th aperture becomes a value satisfying conditions of expressionI, and a focus position P is moved in accordance with the voltage V. By this quick-response electrooptic effect, a small-sized and light-weight optical scanner is obtained which scans in a high speed with a low applied voltage and does not require a condenser lens. In an expressionI, (m), (n), gamma, xsi, lambda, and Xm are an odd, the effective refractive index, the electrooptic coefficient, the coefficient of overlapping beween the field distribution and the refractive index distribution, and the length from the zone boundary to a center O of the scanner respectively.

Patent
23 Oct 1982
TL;DR: In this paper, the alignment reference point of the mask and the wafer is illuminated by two simple color lights with different wave length and the image of each location data is formed on the same plane through the intermediary of the Fresnel zone plate.
Abstract: PURPOSE:To detect the relative position with high precision by a method wherein the alignment reference point of the mask and the wafer is illuminated by the two simple color lights with the different wave length and the image of each location data is formed on the same plane through the intermediary of the Fresnel zone plate. CONSTITUTION:The Fresnel zone plate 11 with the focus f1 is arranged on the image forming location against the single color lights 5 with the wave length of lambda1 to focus on the alignment reference point 2 of the mask 1. Assuming the distance between the mask 1 and the wafer 3 to be d, the single color light 6 with the wave length lambda2 meeting the Formula f1.lambda1=(f1+d).lambda2 is illuminated to form the image against the alignment refernece point 4 of the wafer 3. Thus the location data on the alignment reference points 2, 4 are made parallel with each other to be focussed on the receiving surface of the photoelectric detector 13 by the relay 12 forming the image. The Fresnel zone plate is provided corresponding to the alignment reference points exceeding three and the shutters 7, 10 are successively opened and closed for memory and processing of the data to detect the relative location of the mask and the wafer easily with high precision.


Patent
23 Oct 1982
TL;DR: In this article, the alignment reference points 2, 4 on the mask 1 and the substrate 3 are illuminated alternately at the short time interval by the single color light with the wave length of lambda1, lambda2 through the shutters 7, 10 synchrinized with the opening and closing of the switches 26, 27.
Abstract: PURPOSE:To align the position by a method wherein the first and the second single color light are changed at the short time interval, synchronized to change the output signal of the photoelectric detector for the mask and the wafer detecting the mutual location of each alignment reference point. CONSTITUTION:The alignment reference points 2, 4 on the mask 1 and the substrate 3 are illuminated alternately at the short time interval by the single color light with the wave length of lambda1, lambda2 through the shutters 7, 10 synchrinized with the opening and closing of the switches 26, 27. The location of the Fresnel zone plate 11 and the distance between the mask 1 and the substrate 3 are selected to form the images of the alignment reference points 2, 4 on the receiving surface of the photoelectric detector 13. The resultant output is A/D converted 28 and alternately switched 26, 27 to collect the data on the mutual location. Besides, the alignment reference points may be provided on the locations exceeding three to arrange the Fresnel zone plate respectively corresponding to said points aligning the relative locations in the x, y, and z directions.

Patent
15 Jul 1982
TL;DR: In this article, a Fresnel ring zone plate for X-ray was obtained by forming a concentric pattern of a ring-zone plate which is caused by the intereference of a spherical wave and parallel beams of the interfering beams in a visble range and then reducing the pattern down to a level suitable to an Xray wavelength.
Abstract: PURPOSE:To obtain a Fresnel ring zone plate for X rays, by forming a concentric pattern of a Fresnel ring zone plate which is caused by the intereference of a spherical wave and parallel beams of the interfering beams in a visble range and then reducing the pattern down to a level suitable to an X-ray wavelength CONSTITUTION:A visible beam sent from a laser beam source is splitted to two beams by a semitransparent mirror 1 One of these two beams is focused to a focal point of a lens 9 via a mirror 6, lens systems 7 and 8 plus a mirror 5 and then turned into a spherical wave to iradiate a photographic plate 12 The other beam irradiates the plate 12 as a parallel beam via the mirrors 3 and 4, lenses 10 and 11 plus a semitransparent mirror 2 The mirrors 3 and 4 are controlled with the observation through a telescope 13 so as to obtain the minimum or maximum intensity at the center part A Thus obtained pattern of hologram is reduced down to a level suited to the wavelength of X rays In such way, a Fresnel ring zone plate for X rays is obtained

Patent
30 Jun 1982
TL;DR: In this article, a rod-shaped sample is attached to the rotary shaft of a rotary device and a high degree of vacuum is secured within a container, then the sample 29 is rotated in 300 rotational frequency while measuring the diameter through a microscope.
Abstract: PURPOSE:To obtain a Fresnel zone plate having <=0.1mum image resolution, by coating alternately a light shielding member and a light producing member having a prescribed absorbing coefficient on the circumference surface of a rod- shaped matter and then cutting the rod-shaped matter at the face vertical to the axial core of the rod- shaped matter to obtain a flake. CONSTITUTION:A rod-shaped sample 29 having about 10mum.phi at the area measuring about 0.5mm. from the tip is attached to the rotary shaft of a rotary device 27, and a high degree of vacuum is secured within a container 20. Then the sample 29 is rotated in 300 rotational frequency while measuring the diameter through a microscope 35. Thus the sample 29 is etched to a desired diameter. Then the sample 29 is rotated in 100 rotational frequency, and at the same time Be is coated in 1.196mum by means of an vapor-deposition material source 23. Thereafter, Au is deposited in 0.918mum by the vapor-deposition material source 22. In such way, Be and Au are deposited alternately with a prescribed thickness up to 1,000 layers of coating, and Au is deposited in 0.0456mum at the 1,000th layer. Then the sample 29 is detached from the rotary shaft and buried into the center of a glass or metallic cylinder and cut into a disk shape including the vapor-deposited tip area. Then the single side of the disk is polished into a mirror surface and then adhered to a glass plate with an organic adhesive.

Journal ArticleDOI
TL;DR: In this article, a coded image of a radioactive distribution is created using a single linear Fresnel zone plate and decoding procedure is performed using a computer algorithm simulating the optical phenomenon.

Journal ArticleDOI
TL;DR: In this paper, the frequency response of cylindrical Fresnel lenses with up to 16 steps is calculated with the values measured on a three-step lens, in good agreement.

Book ChapterDOI
01 Jan 1982
TL;DR: In this paper, a spatial focusing electrode pattern, such as a Fresnel zone plate, is used to excite the piezoelectric transducer of a positively scanning transmitter.
Abstract: The resolution of acoustic images from a “positively scanning transmitter” system is limited by the size of the focal spot of the acoustic beam. Frequently a spatial focusing electrode pattern, such as a Fresnel zone plate, is used to excite the piezoelectric transducer of such a system. However, the transformation of that electrode pattern to the acoustic pattern actually generated is not exact. This effect, called mechanical aberration, is a result of wave generation and propagation in the piezoelectric plate and can be represented by a spatial transfer function. The aberration enlarges the focal spot and decreases the resolving power of the instrument.

Book ChapterDOI
01 Jan 1982
TL;DR: The development of tomographic methods has led to considerable progress in medical diagnosis based on external exploration but nuclear medicine has a fundamentally functional vocation as opposed to the morphological exploration methods (X-rays, echography).
Abstract: The development of tomographic methods has led to considerable progress in medical diagnosis based on external exploration. Among these examinations, nuclear medicine has a fundamentally functional vocation as opposed to the morphological exploration methods (X-rays, echography). The result is a high diversity in the nature itself of the study (scintigraphy).