SU920367A1 - Interferometer for for checking concave spherical surfaces - Google Patents

Description

(54) INTERFETOMETER FOR CONTROL OF CONCURSED SPHERICAL SURFACES

I

The invention relates to optical instrumentation and is intended to control. forms of high aperture concave spherical surfaces.

A known interferometer for controlling the quality of concave Spherical surfaces, containing a source of monochromatic radiation, a focusing lens, a cube shaped light emitter formed by gluing two rectangular prisms, a reference spherical mirror and an interfacing card recorder 1.

The disadvantages of the known interferometer are the limited range of apertures of the tested surfaces, relatively low accuracy and productive control. These drawbacks are due to the fact that the cube introduces a spherical aberration into the beam and imposes such high demands on the quality of its manufacture that they are difficult to implement in practice.

The closest to the invention to the technical essence is an interferometer for the control of concave, cross-sectional surfaces.

containing a source of monochromatic radiation and successively located along the course of radiation from the source, a lens and a beam splitter, at one radiation output from which the lens is mounted, on the other - an interference pattern recorder 2.

The disadvantages of this interferometer are the limited range of apertures of the tested surfaces; the accuracy and productivity of the control are relatively low;

This is due to the high demands placed on the accuracy of the beam splitter and the complexity of the alignment process; ferometer

The aim of the invention is to extend the di.

T5 apazona controlled surfaces, improving the accuracy and performance of control.

Claims (2)

This goal is achieved by the fact that in an incrferometer containing a source of monochromatic radiation and successively located in the course of radiation from the source, a lens and a beam splitter, at one radiation output from which the lens is installed, on the other - an interferometric image recorder the lens is facing the beam splitter, the radius of curvature of the lens surface is determined from the ratio Pl (P ;,, deCnl-I) (Pl Ps. (1g-C1l is the absolute value of the radius concave over lens heights; - absolute magnitude of the radius of the convex lens surface; - lens thickness; - beam splitter thickness; lens refractive index; - beam refractor index, phone The optical diagram of the interferometer is shown in Figure 1. performed in the form of a cube, menicon neaplanatic lens 4, the interference pattern recorder 5. The interferometer works as follows. The radiation from the source 1 is focused by the lens 2, passes through the beam splitter 3, the lens 4, and is directed to the test surface 6. The radiation reflected from the convex surface of the lens 4 forms the reference wave front of the comparison. The radiation from the radiation from the controlled surface 6, forms the wave front under study. The studied and reference wave fronts interfere with each other and form an interference pattern, for registration of which the recorder 5 is an interference pattern. By the form of the interference pattern, the shape of the test surface is judged. The increase in control productivity is achieved by the fact that the process of adjusting the interferometer is considerably simplified and reduces essentially to combining the autocollimation point from the convex lens surface with the objective point of the lens. Claims of the invention An interferometer for monitoring concave sphere surfaces containing a source of monochromatic radiation and a lens and a beam splitter sequentially arranged along the radiation path from the source, at one radiation output from which a lens is mounted, on the other an interference pattern recorder, characterized in that expanding the range of controlled surfaces, improving the accuracy and performance of the control, the lens is made meniscus neaplanatic, concave lens surface facing the beam splitter, the radius of curvature of the surface of the lens 1 is determined from the relation, n (.X А-g- A п- (П-й) -4 dteCnl-) СПЛПс) С „-СГл-) the absolute value of the radius of the concave surface of the lens; the absolute value of the radius of the Ash-shaped surface of the lens; lens thickness; thickness splitter; {felomlenia lens value; the refractive index of the beam splitter. Sources of information taken into account during the examination 1. Optical-mechanical industry, 1973, NO 8, p. 50-58. 2. USSR author's certificate ff 373519, cl. G 01 B 9/02, 07/19/73 (prototype).