SU1500971A1 - Light-deflecting device - Google Patents

Abstract

The invention relates to optical instrumentation and can be used in optical systems for deflecting light rays. The aim of the invention is to provide parallel displacement of the beam. The device comprises a working body 1, electrodes 2 connected to a voltage source 3, a light source 4, input and output prisms of radiation, and a segment of a cylindrical lens 7 with parabolic mirror surfaces 8. 2 Il.

Description

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The invention relates to optical instrumentation and can be used in optical systems to deflect light beams.

The purpose of the invention is to increase the diameter of the deflected beam.

FIG. 1 shows the proposed device in FIG. 2 - the same, bottom view.

The device comprises a working body 1, electrodes 2 connected to a voltage source 3, a light source 4, a radiation input prism 5, a radiation output prism 6, and a segment 7 of a cylindrical lens with parabolic mirror surfaces 8.

The working body 1 is made of an electro-optical material, in which, under the action of an applied voltage, an optical indicatrix is rotated in the Strekosti FIG. 1.

The light source 4 comprises a laser, a telescopic system for expanding the beam, a polarizer, and a diaphragm. The telescopic system is anamorphic; it is intended to form a beam section in the form of a rectangle with a length of a side parallel to the plane of FIG. 1. Radiation-plane-polarized with the electric vector, lying in the plane of rotation of the indicatrix of the working medium 1. The range of the used wavelengths is visible and the infrared region.

Prisms 5 and 6 are designed to match the crystal and air optical media.

Segment 7 of a cylindrical lens is made of glass. Surfaces 8 are parabolic. The line (point) of the 9 main focuses of the surfaces 8 is located on the middle of the plane of the working fluid in contact with the flat surface of the segment. .

The device works as follows.

A light beam 10 with a rectangular cross-section comes from the source 4 of the light through a prism 5 into the working body.

The input beam of the light beam 10 forms an angle with the normal to the forming non-zero cylindrical segment 7, therefore the optical path of the beam inside the device represents

There is an eight-shaped multi-turn broken line that starts on prism 5 and ends on prism 6.. After prism 5, the light beam travels the path (along the central beam)

through points 11 ,. 12, 13, 14, 16 and gets to point 17, after which the beam goes to the next turn, ending it at point 18, and at the last turn passes the output prism 6, falls into the zero output position 19. At the same time on the line (point) the main foci of the surfaces 8 are satisfied with the Brewster condition, as a result of which there is no loss of reflection light, and at points 17 and 18 the condition of complete internal reflection is not satisfied. Thus, the energy loss is associated almost exclusively with absorption in glass, which does not exceed 5% per 1 m of the optical path (the second category in terms of light attenuation). The distance between points 17 and 18 is equal to the height of the light beam cross section.

When voltage is applied to the electrodes 2 in the working body 1, an induced birefringence occurs, equal to

   eTTiyi

iL

.Dp

n Cij sin2i /

2

Q

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13 E

where n is the refractive index of a beam propagating at an angle ((;

electro-optical coefficient-,

electric field intensity: As a result, the light beam experiences induced refraction at points 11, 12, 9, and 16, all deviations in phase, and are also matched to the path in the cylindrical segment 7. The beam deflection angle at points 9 and 11 is equal to

L 1/9 dtfn 24n / ri tg tf,

a at points 12 and 16, the deflection angle of the beam is

L (,,

 2 Lp / n ctg tf

where dtf.- is the angle of beam slope by a separate face. The sum of the deviation, we get the value of the deviation l Cf. beam in one pass working body

(f, 4

HRV

Consequently, the total angle D деф deflection in the air will be equal to

; ZZ, where k is the number of turns.

A beam of light, coming out of the deflector, falls into position 20, a. when changing the sign of the voltage, to position 21. When this happens, it practically does not shift in the output aperture, i.e. The beam width can be commensurate with the width of the leg of the prism 5, and there is no vignetting.

We present numerical estimates. Let the working wavelength L be 1.06 μm, the beam diameter 1 mm. The material of the cylindrical segment is K8 glass (p 1.506), the material of the working medium is barium niobate sodium (n 2.2b in the direction of interest). Dimensions of the working fluid: 4, mm, height 5 mm. The angle of incidence of the beam on the boundary of the crystal - glass in the glass if, in the crystal

while fulfilling the Brewster condition. The value of the electro-optical coefficient g. - 80%

 m / V on L 1.06 µm at room temperature. Consequently,

HHGF, A 0.35k-EKB / CM I.

For example, at E 20 kV / cm and K 3

& (f 24 degrees, and when changing the sign of the voltage - 48 g-rad.

Thus, while maintaining the parameters of the deviation, the device allows working with beams of considerable diameter and efficiently using the volume of the working fluid.

The proposed device can be effectively used in ka -V

N H.

 7

Compiled Editor A.Revin Tehred M.Hod

as an independent unit in optical systems for image processing and switching optical signals, in optical storage devices, etc. The solid-state rigid structure of the proposed device is not sensitive to vibration, which allows the device to be mounted

in the transported devices. The materials used in the device have high radiation durability, therefore it is possible to use the proposed device in projectors.

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Claims (1)

Invention Formula Light-guiding device, co. A holding electro-optical working medium with electrodes connected to a voltage source, radiation input and output prisms located on the working body, characterized in that, for the purpose of magnification; the diameter of the deflectable beam, a segment of a cylindrical lens with parabolic mirror surfaces, directed oppositely, installed so that. the forming lens is parallel to the lateral face of the working fluid, and the common line of the main focuses of parabolic surfaces is located in the middle of the plane of the working fluid in contact with the flat surface of the segment of the cylindrical lens. / U / G9 te 17 Proofreader M. Pojo Order 4862/41 Circulation 513 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab., A / 5 Subscription