RU1777114C - Two-coordinate deflector - Google Patents

Abstract

Use: to control the radiation pattern of a light beam. SUBSTANCE: two-coordinate deflector consists of two deflecting crystals, between which a polarization rotator and an optical matching system are placed, which transfers the image of the center of the first crystal to the center of the second crystal. The optical matching system is made in the form of a non-aligned block - two prisms rigidly connected to each other by an adapter tube on which two cylindrical lenses of the matching system are mounted. 1 ill.

Description

The invention relates to optical devices, in particular to devices for controlling the radiation pattern of an optical beam.

Electro-optical two-coordinate deflectors are known (see, for example, Rebrin Yu.K. Control of an optical beam in space. - M.: Soviet radio, 1977, p. 71, fig. 3.13), consisting of two deflecting crystals located in one line and deflecting the light beam in two orthogonal directions. In such devices, at large beam deflection angles, the light beam leaving the first crystal can go beyond the input aperture of the second crystal, which makes it necessary to be limited by small deflection angles or increase the transversedimensions of the second crystal, which entails a sharp increase in the cost of the crystal and an increase in the control voltage.

Closest to the claimed device is a two-coordinate scanning device taken as a prototype (see

Rebrin Yu.K. Optical beam control in space. - M .: Soviet Radio, 1977, p. 41. Fig. 2.10), consisting of two deflecting crystals and an optical matching system. The disadvantages of the described device are that in order to minimize the dimensions of the device, radiation is focused either inside the deflecting crystal or directly near its surface, which reduces the allowable power of the controlled radiation. In addition, it is necessary to use four lenses in the described device (a fourth lens converts the output beam into a parallel one), introducing additional slits and distortions into the structure of the radiation wavefront. The location of two crystals and the optical matching system in one line leads to the fact that the dimensions of the device significantly exceed the total length of two deflector crystals. Due to the presence of a greater number of optical elements, many of which require independent adjustment (L

WITH

h vj vj

-N

leveling devices, the described device is sensitive to the effects of misaligning factors, such as vibrations, accelerations, thermal effects, etc.

The aim of the invention is to increase the permissible power of controlled radiation, to reduce light losses and wavefront distortions, as well as to increase the resistance of the device to misalignment.

The goal is achieved in that the two-coordinate deflector, including two deflecting crystals, a polarization rotator and an optical matching system, is designed in such a way that the optical matching system is a non-aligned device made in the form of two prisms rigidly interconnected with installed prisms on them with two cylindrical lenses.

At Mertezh an optical diagram of a two-coordinate deflector is presented.

The two-coordinate deflector consists of deflecting crystals 1 and 2 with a polarization rotator 3 located between them and an optical matching system. The optical matching system is made in the form of a non-aligned block - prisms 4 and 5 connected by a tube b, and two identical cylindrical lenses 7 and 8 are installed on the prisms. All elements of the optical matching system are interconnected in one piece (adhesive, optical contact, etc.). P.). The dimensions of the prisms and the length of the tube are such that the distance between the lenses (taking into account the control in the prisms) is equal to the double focal length of the lenses. The deflection crystals are arranged so that the distance from the center of the first crystal 1 to the first lens 7 (taking into account the elongation in the crystal) is equal to the distance from the second lens 8 to the center of the second crystal 2 (taking into account the elongation in the crystal and the polarization rotator) and equal to the focal length of the lenses.

Two-axis deflector works

in the following way. A parallel light beam deflected by the first crystal in the plane of the pattern hits the lens and focuses in the center of the connecting tube, then it is converted by the second lens

into a parallel beam and through a polarization rotator, which rotates the plane of polarization by 90 °, are sent to the second crystal, deflecting the light beam in a plane perpendicular to the plane

drawing. In this way, the image of the central section (in which the effective beam deflection center is located) of the first crystal is transferred to the central section of the second crystal.

The device is significantly less critical for misalignment, and the minimum number of optical surfaces introduces less loss and distortion of the wavefront.

Claims (1)

SUMMARY OF THE INVENTION A two-coordinate deflector consisting of two deflecting crystals with a rotator located between them polarization of two cylindrical lenses, the generators of which are parallel, and an optical matching system, characterized in that, in order to increase the allowable power of the controlled radiation, as well as to reduce light losses and wavefront distortions, the optical axes of the crystals are parallel, and the optical matching system is made U-shaped and consists of two rectangular prisms, the input faces of which are perpendicular to each other, with cylindrical lenses mounted on the input face of the first prism and the output face of the second prism.