Сдвиговый спекл-интерферометр с квадролинзой

The paper proposes a new optical element – Quad lens, which is used as part of a shearing speckle interferometer (sherograph) to provide measurements of stress-strain states of objects simultaneously in two mutually perpendicular directions. Quad lens consists of four identical sections cut from the original round lenses and spaced from each other to form a gap. Quad lens creates four images of an object that are offset relative to the optical axis by a distance that depends on the size of the gaps between the sectors. Phase recovery from a single speckle interferogram is performed using the spatial phase shift method based on the Fourier transform. To increase the contrast of interference bands, an aperture diaphragm with four holes is installed in front of quad lens sectors, and polarizing channel isolation can be used to separate channels and reduce the influence of cross interference. Experimental results of using a speckle interferometer with quad lens for the study of microdeformation of a round membrane are presented.

Imaging Analysis and Application of Digital Speckle Photography with EALCD

According to the principle of speckle photography, CCD(Charge-Coupled Device) as a recorder, and EALCD(Electrically Addressed Liquid Crystal Display) as a read-out element, which makes the speckle photography to digital. Recording light path of the subjective and the objective speckle and observation light path of full-field analysis and point-by-point analysis for fringe reconstruction have been respectively researched. At the same time, measuring by speckle photography, the fringes in the interometry pattern must be carefully analyzed. Since the speckle noise can greatly infect the signals. Thus to de-noising the speckle fringe by a suitable filter before processing is expected. The mathod of digital filter enhancement, smooth denoising be used to reduce the influence of the high noise and the inhomogeneous grey of the speckle interferogram. Finally the thinning fringe is acquired, the fringe spacing is extracted accurately, the three-dimensional measurement of a deformed object is realized with mathematical morphological thinning algorithm.

An Image Reconstruction for Capella with the Steward Observatory/AFGL Intensified Video Speckle Interferometry System

In the decade since its invention by Labeyrie in 1970, speckle interferometric techniques have evolved from simple optical processing of photographic images to high-speed digital processing of quantum-limited video data. This progress has been summarized in preceeding papers by McAlister and Weigelt in this colloquium.The basic hardware of our system has been described in Hubbard, et al. (1979 – The basic speckle camera) and in Hege et al. (1980 – The intensified video system). These capabilities have been successfully applied to observations over a dynamic range of 16 magnitudes, from Betelgeuse (Goldberg, et al. 1982) and Capella (this paper), at one extreme, to Pluto/Charon (Hege, et al. 1981a) and the 16th magnitude resolved QSO system PG1115+080 (Hege, et al. 1981b) at the other. To accomodate this dynamic range two distinct data-recording/data-processing modes have been implemented. The Analoue mode records the image intensity for each pixel in the speckle interferogram. This is applicable for objects brighter than 7th to 10th magnitude, depending upon telescope aperture, observing band-pass and detector image scale. For fainter objects the Event mode records individual photoelectron addresses in the speckle interferogram.