SU1756850A1 - Optical delay line - Google Patents

Abstract

The invention relates to elements of optical computing devices. The purpose of the invention — reduction in size when used in optical computing devices — is achieved by repeatedly re-reflecting the light beam from the mirrors. The device contains mirrors 1,2,3, 4, made in the form of pairwise equal rectangles connected by ends with the formation of a rectangular parallelepiped, in the corner of mirror 1 the input window 5 is made, and the output window b is executed or in the opposite corner of mirror 1 along its diagonal , or in the corner of a mirror 3 diagonally parallelepiped. The length of the sides I of the input 5 and output 6 windows is determined from the relation where c is an overall 2 Mp vT coefficient; a, b, c is the length, width and height of the parallelepiped; T is the required delay time, m is the absolute refractive index of the medium of propagation of light between the mirrors; v is the speed of light in vacuum. And the direction of the light beam at the entrance to the device is given by the angles determined from the ratios tg / 3 cos av о гь2 + 2tg (Л С cos у 2/2 a Vb2 + I2 + 4/2 а, 3 Cpf-ly, beat

Description

Fig 2

The invention relates to optical elements and can be used in devices for optical information processing, for example in optical computing devices that require a signal delay for some time.

A known optical delay line in the device comprises a bar of transparent material installed along the light beam, the optical density of which is greater than the optical density of the medium of propagation of light outside this bar. This line has a significant size, which makes it difficult to use it in many optical processing devices.

An optical delay line is also known, containing four mirrors mounted at the vertices of a quadrilateral at an angle of 45 ° to the optical axis of the device with reflective surfaces facing each other, the input and output windows being made in one mirror. The overall dimensions of this delay line are subject to sufficient delay tahzhe very large

The purpose of the invention is to reduce the size when used in optical computing devices.

This goal is achieved by the fact that in an optical delay line containing four flat mirrors installed perpendicular to one common plane and optically conjugated with each other, the opposite mirrors being mutually parallel, and the adjacent mutually perpendicular, as well as the input and output windows of the mirror in the form of pairwise equal rectangles connected by ends with the formation of a rectangular parallelepiped, and the length of the sides f of the input and output windows is determined from the ratio

 - vT

where M is the dimensional coefficient (M a-b-c),

a, b, c are sides of the parallelepiped;

n is the refractive index of the medium inside the parallelepiped;

v is the speed of light in a vacuum;

T is the delay time.

and the angles between the sides of the parallelepiped and the light beam entering the delay line are determined from the ratios

and arccos

B2 + (2 + ta1

one

/ 3 arctg

12 +

at arccos

Ј, 3

 +

2a

where a is the angle between the light beam and the direction of the edge a;

/ is the angle between the ray of light and the direction of the edge b;

y is the angle between the ray of light and the direction of the edge c;

I is the length of the side of the input window. FIG. 1-3 shows the light of the light through the device and the location of the input and output windows; figure 4 - scan the device along the axis OX; Fig. 5 is a diagram for determining the guide angles.

The device consists of mirrors 1-4 of rectangular shape, which are connected in such a way that they form a rectangular parallelepiped with sides a, b, c, 8 corner of mirror 1 with dimensions made transparent entrance window 5 with dimensions 1x1. The output window can be made in the opposite corner of mirror 1 (assuming an odd number of reflections from mirrors 1 and 3), or in the corner of mirror 3 diagonally on the parallelepiped (with an even number of reflections from mirrors 1 and 3). In order to simplify the design, all mirrors are made on a common substrate,

which is a rectangular parallelepiped of transparent material, such as Kzar, with the reflective layer applied on the edges of the parallelepiped with the dimensions of echo and VX,

The device works as follows.

The beam of light enters the device through the center of the entrance window 5, forming the corners of a-with the side of parallelepiped a, f3- with the side of parallelepiped B.-with side 4 of parallelepiped. The beam is then repeatedly reflected from facets 1 and 3, reflected from rooks 2, again from rooks 1 and 3, from face 4 and so on until it leaves through exit window 6.

Claims (3)

Claims 1. An optical delay line containing four flat mirrors installed perpendicular to one common and optically conjugated with each other, the opposite mirrors being mutually parallel and the adjacent mirrors mutually perpendicular, as well as the input and output windows, which are different in order to reduce overall dimensions when using 6 in optical computing devices, the mirrors are made in the form of pairwise equal rectangles joined by the horizontally to form a rectangular parallelepiped, and the length of the sides I of the input and output windows is determined from the ratio vT where M is the dimensional coefficient (M AhVhS); A, B, C - sides of the parallelepiped; g is the refractive index of the medium inside the parallelepiped; v is the speed of light in a vacuum; T is the delay time The direction of entry of the light beam into the entrance window is determined by the following angles: I a - arccos / b2 + l2 ; 2a at arccos - - V 2a g. Fig.Z where a is the angle between the ray of light and the direction of the edge, a; / is the angle between the ray of light and the direction of the edge, b; y is the angle between the ray of light and the direction of the edge, s; I is the length of the side of the entrance window. 2. Delay lines according to claim 1, characterized in that the output window is made in the same face of the parallelepiped as the entrance window and located in its opposite corner. 3. Delay lines according to claim 1, about tl and w, and with the fact that the output window is in the face of the parallelepiped, parallel to that in which the input window is made, and located in its opposite corner diagonally of the parallelepiped. A. Line delays in paragraphs. 1-3, of which is so. that, in order to simplify the construction, all the mirrors are made on a common substrate, which is a rectangular parallelepiped of transparent material, while the reflective layer is made on the edges of the parallelepiped with dimensions а х с and в х с. AT , "ABOUT ABOUT BUT L