Kiyofumi Matsuda

Holographic Generation of Contour Map of Diffusely Reflecting Surface by Using Immersion Method

This paper describes the double exposure holographic formation of a contour map over a diffusely reflecting or transmitting of arbitrary shape and surface finish by using an immersion method with media of different indices of refraction between successive exposure. A wavelength λ effectively contributing to the fringe contour is given by λ0/Δn where λ0 is the wavelength of the laser and Δn is the index variation. Index variations were introduced by pressure difference in Freon to give λ=600 µ and 200 µ, and by the combination of two liquids to give 14 µ and 25 µ, thus extending the change of height corresponding to each fringe contour continuously up to one thousand times greater than with the optical Fizeau fringes. A correcting plate of a Schmidt camera in the grinding process was used as a test object and its figuring error were analyzed.

The Application of Phase-only Filters to Optical Interconnects and Pattern Recognition

Abstract We have recently developed a new type of liquid-crystal spatial light-modulator which acts as a phase-only spatial light-modulator for coherent light. The use of this device as a flexible filter in the Fourier plane of an optical correlation system is described, and it is shown how it may also be used as a flexible interconnect capable of simultaneously providing continuous amplitude and binary phase modulation.

Apparatus for three-dimensional viewing of magnetic resonance imaging tomograms

A plurality of liquid crystal displays, each able to independently display one of a plurality of MRI tomograms, is dispersed such that the display screen of each appear planar from a common point and are positioned such that the spacing between each display screen and the next one in front or back and of it is proportional to the spacing between the cross sections belonging to the MRI tomograms displayed by those display screens. A hologram screen is provided in position facing the display screens of the plurality of displays. By illuminating the plurality of displays with light from behind, light passing through each of the display screens will impinge on the hologram screen, and part of this light will be diffracted backwards by the hologram screen, causing virtual images of the MRI tomograms to appear in front of the hologram screen.

Correlation Techniques by Holography and its Application to Fingerprint Identification

The optical correlation technique is a powerful means for optical pattern recognition [1][2], and holography brings a new and precise method known as optical matched filtering [3] using a Fourier-transform hologram.

A Method for Detecting Microstructure Deformation in Diffuse Objects by Holographic Interferometry

In holographic interferometry, interference fringes of equal inclination are produced from a double exposure hologram recorded before and after the movement of a diffuse object. These fringes, however, can also be obtained by the movement of a photographic plate on which the hologram is to be recorded and this movement is useful when the movement of the object is not possible. This paper discusses a method for detecting the degree of deformation from the decrease of the visibility of these fringes and for measuring the area of deformation by using the subtraction processing. An application to the electrochemical polishing is proposed.