SU469882A1 - Helographic interferometer - Google Patents

Description

elements: both stored in front of object 7, and recording medium 8.

The coherent radiation of laser 1 is collimated by the optical system 2. With the aid of the beam splitter plate 3, the collimated beam is divided into two beams, which, after reflection from 4 and 5, are set on the recording medium 8.

The signal plane beam / o at the output of the optical element 6 forms a set of elementary planes: their waves, paonipocTransienting at different angles in several directions. The object under examination is illuminated by a combination of such light waves. In the plane of the recording medium, elementary plane waves and heat with the reference light wave. In this case, an aggregate of the following: Pram1M simultaneously is recorded on the photographic plate, each of which corresponds to a specific direction of translucency of the object.

At the stage of recovery of wave fronts (see Fig. 2), the hologram is transmitted only with the reference beam / o. Information about the object is obtained with the help of an about: lens 9 and spatial filters 10, 11 installed in its focal plane 12. By moving the spatial filters along the signal spectrum, various interference / patterns are obtained in the selected object translucency directions (vertical, horizontal and oblique). Each interferogram obtained in a certain direction characterizes the integral distribution of the field of the refractive index along the propagation of the light beam.

The optical element 6 installed in the proposed interferometer, can be manufactured in a holographic way. The photographic plate records the result of the interference of two plane wave fronts. At the first ecoposition, interference fringes (eg, vertical) are recorded. Before the second exposure, the photographic plate is rotated around the optical axis at any angle, for example, 90 °. After that, the plate is photographed. And it is processed and excreted. Then, on its surface, a relief is obtained by bleaching in a weak solution of red blood salt. The optical element obtained in this way is a phase raster containing two periodic systems of linear elements. FIG. 3 schematically depicts the phase

raster The raster surface is a collection of elementary light sources. In the case of regular periodic systems of line elements, each elementary source has a square shape.

The drawing also shows how the incident wave is decomposed by a single elementary source. The angles a and характериз 3 characterize the deviations of the light rays ne (of the ryh diffraction orders in the horizontal and vertical directions, respectively. In the case of regular periodic systems of linear elements, the angles a and p are equal.

Thus, the holographic interferometer with the phase raster in front of the object

allows one hologram to simultaneously obtain different interfacial patterns in several directions of the translucency of a spatial object.

Prev Invention

A holofaphichesky interferometer for the investigation of spatial phase objects, containing a source of coherent radiation,

a beam-splitting plate, an optical system for generating reference and signal beams, a periodic structure in front of an object, such as a diffraction grating, and a recording medium that differs

the fact that, in order to determine the parameters of the object under study in any plane of the field under study, the periodic structure is made of two-dimensional myofrequency, for example, from two periodic systems of linear

elements oriented at an angle to each other.

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