SU1516806A1 - Device for transmitting dimension of average power unit of laser radiation by measuring means - Google Patents

Abstract

The invention relates to a measurement technique and can be used to calibrate and certify means for measuring the power of laser radiation. The purpose of the invention is to improve the accuracy of the unit size transfer. In a device containing a laser, a diffraction grating for dividing its radiation power, a reference and a tunable radiation receivers, the diffraction grating is installed perpendicular to the optical axis of the laser with the possibility of rotation around this axis and fixing in two positions that differ from one another by 180 °. The grid is made reflective. The invention makes it possible to eliminate the error associated with the determination of the intrinsic sensitivity of the reference and calibrated receivers and the non-ideality of the diffraction grating. 1 il.

Description

The invention relates to a measurement technique and can be used to calibrate and certify means for measuring the power of laser radiation.

The purpose of the invention is to increase the accuracy of unit size transfer.

The drawing shows a block diagram of a device for transmitting the size of a unit of average laser power by measuring means.

The device contains a laser 1, a reflecting diffraction grating 2 installed along its emission. In one of the first grating diffraction orders, a reference radiation detector 3 is installed, and in a symmetric

In the order of diffraction of the grating, an assembly is installed for installing the measuring means 4 to be installed, which is installed at the same distance 1 from the diffraction grating 2 as the reference radiation receiver 3. The diffraction grating 2 is installed in the mandrel 5 perpendicular to the laser axis. The mandrel 5 is equipped with a drive 6 of its rotation relative to the laser axis and clamps 7 for rigid installation of the mandrel in two positions a and b, differing from each other by 180. A quarter-wave plate 8 is installed between laser 1 and grating 2 to eliminate the effect of the zero diffraction pattern on the stability of the source 1. Diffraction Cit

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The grating is made, for example, on a glass substrate, on which, for example, strokes with a depth equal to a quarter of the laser wavelength 1 are applied by ion etching. Choosing this depth of strokes suppresses the power reflected in the zero diffraction order and concentrates it in the first diffraction orders. By appropriate selection of the number of strokes per millimeter, elimination of higher diffraction orders is achieved. The drive 6 of the mandrel may include, for example, a bearing support and a drive brush that can be moved manually or at rest of the actuator. The clamps 7 of the mandrel can be performed, for example, ball.

The device works as follows.

In the process of transferring the size of the unit to the measurable measuring means 4, it is installed in the installation unit intended for it at the same distance from the array as the reference radiation receiver 3. A stream of continuous radiation from laser 1 hits a diffraction grating 2, on which the beam is separated.

The coefficient, P2 division of the diffraction grating, i.e. the ratio of the radiation power, branched to the reference P (radiation receiver 3 and calibrated P. sensitivity, respectively, of the reference receiver 3 and the measured measurement means 4. Turn the diffraction grating 2 around the axis of the laser 1 by 180 and again record the output signals of the receiver 3 and the medium

reference receiver

Here

and

receiver signals J and tva 4 measurements V T, and V G, 5p

From these two measurements, the division ratio is determined.

TO.

RA I Va V

WG N v P

The diffraction grating 2 is set to the initial position, radiation is supplied to it and the output voltages V of the reference receiver are recorded

t

J and V of the verified instrument 4 measurements. According to these measurements using the ratio

K, K TO

where K is a known coefficient characterizing the reference receiver 3;

 R

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Vi

vf

20

d 25 5 30

40

45

50

The equivalence factor K of the test instrument 4 is determined, the determination of which is reduced by the procedure for transferring the size of a unit.

Determining the K coefficient by measuring the output signals at two positions of the diffraction grating allows one to increase the accuracy of the unit size transmission by eliminating the error associated with determining the intrinsic sensitivity of the radiation receivers and the non-ideality of the diffraction grating.

Claims (1)

Invention Formula A device for transmitting the size of an average / laser power unit to a measurement device, comprising a laser, an optically coupled diffraction grating, as well as a reference radiation receiver and an installation unit for a testable measurement tool, installed on opposite sides of the optical axis of the laser at an equal distance from grating in directions that coincide with the diffraction peaks of the grating, characterized in that, in order to improve the accuracy (transmission of the unit size, the diffraction grating is made perpendicular to the optical axis of the laser with the possibility of rotation around this axis and fixing it in two positions differing from each other by 180 °.