Abstract: A deformation measuring method and device in which an object is irradiated with a laser beam before and after deformation of the object to obtain speckle patterns, the speckle patterns thus obtained are photoelectrically converted into electrical signals, and the cross-correlation function between the speckle patterns is calculated using the electrical signals to obtain displacement of the speckle pattern on the basis of the shift of position of the extreme value of the cross-correlation function and to determine the amount of deformation of the object from the displacement of the speckle pattern. Each of photosensitive elements for converting the speckle patterns into the electrical signals has a rectangular form of a large ratio of a long side to a short side and a photosensitive element array comprising the photosensitive elements has a comb structure in which the photosensitive elements having the above structure are arranged in a strip form.

Abstract: In a deformation measuring method and device in which an object is irradiated with a laser beam before and after deformation of the object to obtain speckle patterns, the speckle patterns thus obtained are photoelectrically converted into electrical signals, and the cross-correlation function between the speckle patterns is calculated using the electrical signals to obtain displacement of the speckle pattern on the basis of the shift of position of the extreme value of the mutual-correlation function and to determine the amount of deformation of the object from the displacement of the speckle pattern, (1) the reference speckle pattern data for calculation of the cross-correlation function is renewed when the extreme value of the cross-correlation function is lower in level than a predetermined value or when the position of the extreme value is out of a predetermined range, or (2) the reference speckle pattern data is renewed when the extreme value of the cross-correlation function is lower in level than a pre

Abstract: A realtime monitor of an astronomical object such as a double star using speckle interferometry comprises a TV camera for picking up an image of a star which is formed by a telescope, first means for producing an incoherent still picture of the star on the basis of an output from the TV camea, second means for producing a power spectrum of the star by converting the incoherent still picture to a coherent image and then optically Fourier-transforming it, third means for adding the consecutively produced power spectra to obtain an average power spectrum, and fourth means for controlling first, second and third means and calculating a normalized average power spectrum of an object star through dividing the average power spectrum of the object star by that of a reference star.

Abstract: An optical heterodyne detector comprising means for causing two light beams to interfere with each other and producing interference light beams thereof, a streak camera for receiving the interference light beams and analyzing means for analyzing an output of the streak camera, thereby to detect a beat frequency of the two light beams.