RU1824518C - Method of recording interferograms of objects, made in form of lenses and objectives - Google Patents

Abstract

The invention relates to measuring technique, is intended to control the wave aberrations of positive lenses and lenses, and may find application in the manufacture involved in their manufacture. SUBSTANCE: diffuse scatterer is illuminated with coherent radiation, a diffuser image is formed in the plane of the photosensitive medium with the help of a controlled object with a given focal length f, the speckograms of the diffuser image are recorded on the photosensitive medium, and the specklegram is re-recorded after the controlled object is displaced in its main plane , illuminate the twice-exposed specklegram with a coherent wave and register the interferogram of the control in the far diffraction during spatial filtering, moreover, the diffuse scatterer is illuminated by a convergent spherical wave with a radius of curvature in its plane R Ii2 / (h + l2). where I, 12 are, respectively, the OTL distance of the main plane of the controlled object to the diffuser and the photosensitive medium, and before re-recording the specklegrams, the diffuser is additionally shifted in the direction of displacement of the controlled object by an amount satisfying the ratio b, where a is the displacement of the controlled object of 1 il. (L C

Description

The invention relates to measuring technique, is intended to control the wave aberrations of positive lenses and lenses, and may find application in the manufacture involved in their manufacture.

The purpose of the invention is to increase the sensitivity of control

The drawing shows a diagram of a device that implements the invention. The device comprises a coherent source 1, lenses 2. 3, frosted glass 4 with a mechanism for its movement 5, a mount for a monitored object 6 with its mechanism for its movement, a photographic plate 8.

The invention is carried out as follows. The coherent beam of radiation from source 1 with the help of lenses 2, 3 is transformed into a converging spherical wave of illumination of frosted glass 4 with a radius of curvature in its plane R - -Ii2 / (h + l2), where II, 12 are, respectively, the distance from the main plane of the controlled lenses in the mount 6 to the frosted glass 4 and the photographic plate 8, in the plane of which the image of the frosted glass 4 is built

00

Yu

4 joint venture

with

A speckle record is recorded on photographic plate 8 during the first exposure. Before the second exposure, using movement mechanisms 5, 7, frosted glass 4 and the fastener of the controlled object 6 are displaced in one direction perpendicular to the optical axis according to the ratio b ali / f, where a is the displacement of the fastened node of the controlled object b, with a focal length f, b is the displacement of the frosted glass 4. Moreover, a (f + 1) in / 2, where D is the diameter

pupil of a controlled object. The two-exposure speckleogram recorded in this way is illuminated by a plane coherent wave and the interferogram of controlling the wave aberrations in the far diffraction zone is recorded during spatial filtering, for example, in the focal plane of a lens with a small aperture diaphragm. If the center of the aperture diaphragm coincides with the optical axis, then the lateral shift interferogram is filtered out in bands of infinite width, which characterizes the main wave aberrations of the controlled lens. The displacement of the center of the aperture diaphragm in the direction of the axis of movement of the frosted glass 4 and the attachment site of the controlled object 6 allows you to filter the interference pattern characterizing the combination of

5

0

5

0

axial and off-axis wave aberrations.

Claims (1)

SUMMARY OF THE INVENTION A method for recording interferograms of objects in the form of lenses and lenses, comprising illuminating a diffuse diffuser with coherent radiation, forming in the plane of a photosensitive medium with a controlled object with a given focal length f; diffuser mash. recording on a light-sensitive medium speckle images of the diffuser, re-recording the speckle after moving the controlled object in its main plane, lighting the double-exposed speckle with a coherent wave, and recording the control interferogram in the far diffraction zone during spatial filtering, characterized in that, in order to increase the control sensitivity, the diffuse diffuser is illuminated with a spherical wave with a radius of curvature in its plane R Ii2 / (h + l2), where h, h, respectively but the distance from the main plane of the controlled object to the diffuser and the photosensitive medium, and before re-recording the specklegrams, the lens is additionally shifted in the direction of displacement of the controlled object by an amount satisfying the ratio b ah / f, where a is the displacement of the controlled object. 8 I