SU1613853A1 - Method of compensation of wave front for checking shape of surface of astronomical mirrors - Google Patents

Abstract

The invention relates to a measurement technique and is intended to control the surface shape of concave aspherical mirrors of large telescopes. The aim of the invention is to expand the forms of controlled mirrors due to the possibility of changing parameters of the compensator. To adjust the compensator to control the aspherical mirror with the specified parameters, depending on the positive single lens component used, either the menisci regarding the component in the form of a two-convex lens, or the meniscus positioned between the component in the form of a meniscus or a flat-convex lens and a controlled mirror with the appropriate calculation separating elements of air gaps. 4 hp f-ly, 3 ill.

Description

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with

The invention relates to a measurement technique and is intended to control the shape of the surface of concave aspherical mirrors of telescope telescopes by an interference method.

Pel of the invention is the expansion of the forms of controlled mirrors by providing the possibility of changing the parameters of the compensator.

This goal is achieved by the fact that two single menisci are located between a two-convex lens, fixedly mounted, and a mirror, with the menisci mounted with the possibility of movement along the axis.

In Fig about 1-3 shows the circuit with compensators used in the implementation of the proposed method.

The diagrams indicate the source of light 1, positive single-lens

component 2, made in the form of either a double-convex lens (Fig. 1), or a meniscus (Fig. 2), or a flat-convex lens (Fig. 3), and two single meniscus 3 and 4, facing in concavity to each other

Position 5 marked the surface of the controlled mirror; center of curvature C (5 at the top of the surface .5 is compatible with the image of light source 1; a and b are air gaps separating lens 2 and menisci 3 and 4 respectively; 5 is the rear apex segment of the compensator; Gd is the apical radius of curvature surface 5.

The method is carried out as follows according to the scheme shown in FIG. one.

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The light source 1 is installed in the front focus of the lens component 2, so that a parallel path of the rays between the double-convex lens and the Zo Meniscus 3 U1enisky lens converts the beam of parallel rays coming into it into converging. Meniscus 4 converts the beam of rays arriving at it into a beam, all the rays of which are directed strictly along the normal to the theoretical surface of the mirror. In the process of controlling, the rays of light, reflecting from the surface 5 of the mirror, repeat their path in the opposite direction. These rays create a wave front, carrying information about the error of the monitored surface of the mirror, and leaving the compensator, go to a wave front analyzer, for example, an interferometer (not shown) .. Based on the analysis of the wave front coming out of the compensator, controlled surface of the mirror. When adjusting the compensator to control an aspherical mirror with a given parameter, 1 MI needs to move the menisci 3. and 4 relative to each other and a fixedly set two-convex lens to set the calculated values of the air gap Q and b and to align the image of the light source with the Cp point

According to the schemes shown in FIGS. 2 and 3, the method is carried out as follows.

the way

The light source 1 is installed in the front focus of the meniscus 3, thereby providing a parallel path of rays between component 2 and meniscus 3, Component 2 converts the beam of parallel rays arriving at it into converging about Meniscus 4 converts the beam of rays arriving at it into a beam, all the rays which are directed strictly along the normal to the theoretical surface 5 of the mirror. In the process of controlling the rays of light, reflecting from the surface of the mirror 5, repeat their path in the opposite direction. On the basis of the analysis of the waves coming out of the compensator Vågå front conclude about the quality of manufacturing a controlled my mirror surface. When adjusting the compensator to control the aspherical mirror with the specified parameters, it is necessary to move the components.

nent 2 and meniscus 4 with respect to the fixedly mounted meniscus 3, set the calculated values of air gaps a and 6 and align the image of the source 1 of light with point Cd.

The method allows one to control the shape of the surface of concave aspherical mirrors in a wide range of parameters; it replaces the compensators of individual assignment from T to; To set the compensator to control an aspherical mirror with given parameters, you must move the elements relative to each other to set the calculated values of air gaps a and b and combine the image of the light source with the center of curvature at the top of the mirror surface

Claims (5)

1. A wavefront compensation method for controlling the surface shape of astronomical mirrors, lies in the fact that a lens compensator of two single meniscus faces facing each other, and a positive component, is installed between the radiation sources and the mirror, in that in order to expand the forms of controlled mirrors, the elements of the lens compensator are moved along the optical axis 2. A method according to claim 1, characterized in that the menisci are moved and placed between the mirror and the lens element, which are made in the form of a two-folded line, - zy. 3 „Popo1 method, I differ. u and with the fact that they move the lens element, which is installed between the menisci, and one of the menisci, which is installed between the mirror and the lens element. 4, a method according to claim 3, characterized in that the lens element is in the form of a meniscus and is turned towards the meniscus, which is displaced. 5. The method according to claim 3, wherein the lens element extends into the form of a flat convex lens and turns a flat surface towards a meniscus that is not moved, 1 Sj LHSSZ sm Fal I iiut.3