SU1653000A1

SU1653000A1 - Device for attenuating optical feedback

Info

Publication number: SU1653000A1
Application number: SU894709078A
Authority: SU
Inventors: Юрий Михайлович Климков; Михаил Иванович Шрибак
Original assignee: Московский институт инженеров геодезии, аэрофотосъемки и картографии
Priority date: 1989-06-23
Filing date: 1989-06-23
Publication date: 1991-05-30

Abstract

Изобретение относитс к оптико-электронному приборостроению и может быть использовано при производстве систем оптического воспроизведени информации. Цель изобретени - упрощение конструкции , снижение энергетических потерь. Дл этого блок 2 ослаблени обратного пучка состоит из стопы фазовых дифракционных решеток 3 с шагом d, который определ ют из соотношени А/п d А, где Я - длина волны излучени лазера, п-показатель преломлени материала дифракционной решетки , при этом дифракционна решетка представл ет собой прозрачную плоскопараллельную пластинку, на одну из поверхностей которой нанесен микрорельеф, друга поверхность просветлена, торцовые грани покрыты светопоглощающим слоем, причем дифракционные решетки установлены так, что микрорельеф находитс с противоположной стороны от лазера 1.1 з.п.ф-лы, 2 ил. ч ЁThe invention relates to optoelectronic instrument making and can be used in the manufacture of optical information reproduction systems. The purpose of the invention is to simplify the design, reducing energy losses. For this, the reverse beam attenuation unit 2 consists of a foot of phase diffraction gratings 3 with a step d, which is determined from the ratio A / ndA, where I is the laser radiation wavelength, the n-refractive index of the material of the diffraction grating, em is a transparent plane-parallel plate, on one of the surfaces of which a microrelief is applied, the other surface is coated, the end faces are covered with a light-absorbing layer, and the diffraction gratings are set so that the microrelief is TC on the opposite side of the laser 1.1 Cp f-crystals, 2 Il. h y

Description

Редактор Л. Пчолинска Editor L. Pcholinska

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Составитель Г. Лисенков Техред М.МоргенталCompiled by G. Lisenkov Tehred M. Morgenthal

Корректор М. МаксимишинецProofreader M. Maksimishinets

Claims

Claim

1. An optical feedback attenuation device, comprising an optically coupled • laser, an attenuation unit of the return beam, an optical path with a reflecting element. Characterized in that, in order to simplify the device and reduce the energy loss of the optical feedback, the reverse beam attenuation unit is made in the form of the (1 + 1) th phase diffraction gratings with a step di determined by the formula

L / n <d _£ <A, ¹ 5 where A is the laser radiation wavelength;

η is the refractive index of the material of the diffraction grating;

1 = 0. 1.2 .....

each of which is a transparent plane-parallel plate with a microrelief on one of its surfaces. the other surface of the plate is enlightened, located on the side opposite to the laser, the end faces 25 of this plate are covered with an absorbing layer.

2. Device pop. 1, distinguished by the fact that at i = 0 the microrelief of diffraction

The 30th lattice represents rectangular recesses, the width of which is equal to half the lattice pitch, and the depth h is determined by the formula _u 2 k + 1 A

35 --2 --- py, where k = 0, 1.2, ...;

A is the wavelength of the laser radiation;

p is the refractive index of the material of the diffraction grating.

A