SU393789A1 - METHOD OF MEASUREMENT OF CONSUMPTION OF A RAY OF OPTICAL QUANTUM GENERATOR - Google Patents

Description

one

The invention relates to methods for measuring the divergence of a beam of optical quantum oscillators (JAG) and can be used in quantum electronics and in automatic systems.

The known method of measuring, diverging the beam divergence of optical quantum generators in a single-pulse mode, based on the research of the brightness of the spot at the focus of the lens, consists in splitting the beam into several beams, perceived by the recorders, where a photographic film is used as a recorder.

There is also known a method for measuring the beam divergence based on comparing sigpals in a recording system, where the magnitude of the lens shift determines the angle of divergence of the beam.

However, these methods do not allow measuring the divergence of an individual pulse from a series of light pulses or divergence at any time interval, and also require a long time to measure a single pulse, which makes it difficult to measure this parameter in industrial conditions.

The purpose of the invention is to eliminate these disadvantages.

The essence of the present invention is to develop a method for measuring the divergence of a laser beam, which provides a relatively quick measurement of the divergence at any time interval, as well as an individual pulse. Thanks to the fact that optical signals convert photodetectors into electrical ones, they are isolated, separated, and fed to a recording system, where voltage variations are compared at certain time intervals when the angle between the beam and the receiving part of the photodetectors is changed, from which the divergence of the beam is determined. , from the pulse amplitude envelope.

The proposed method, in terms of the speed of measurement of the divergence, involves the use of oscilloscopes with storage tubes.

The drawing is a block diagram illustrating one of the embodiments of this method.

The circuit includes the generator 1 under study, the long-focus lens 2, of light. separating device 3, adjustable aperture 4, photodetectors 5, output adjustment unit, gating unit 7, consisting in turn of a key block 5 and a strobe generator 9, separation diodes 10, delay lines 11, indicator (oscilloscope) 12.

In cases where the laser works with powerful radiation, an attenuating filter 13 is additionally installed in front of the lens.

The work of this method is carried out as follows. The laser source beam is divided into several beams and converted by photoreceivers 5, located in the focal plane of objective 2, into electrical signals whose amplitude at the same time interval depends on the angular position of the adjustable orifices 4 and on a number of other parameters. From photoreceivers 5, radio signals, for example, strobing, select the signals at the desired time interval or pulses of interest and separate the delay lines so that after dividing them, the signals from each photodetector sequentially arrive at their recording system and on the indicator 12 are observed separately. To ensure separate transmission of signals to the delay lines, the latter arrive at them through separation diodes 10. Equal areas of the diaphragms 4 and equal angular positions of the photodetectors 5 relative to the spot are set, and in these positions the control optical signals, for example, the measured radiation is achieved in the output signals adjustment block 5. Signal amplitudes in amplitude at the intervals of interest, which compensates for the effects on the signals of various unknown parameters.

Depending on the measurement, the divergences in a certain section or over the entire area of the subsequent spots set certain angles. The lateral displacements or different areas of the receiving part of the photodetectors 5, preserving all the others, the parameters without changing, then the changes in the values of the voltages relative to the original signals when the photocopters are operating in linear mode are proportional to

to the particular values of the intensity distribution function of the beam in accordance with the new positions or sizes of apertures.

When calibrating the indicator time axis in angular units, the divergence is determined from the distribution function of the energy or intensity of radiation, which is obtained as the envelope of a series of pulses.

The proposed method for measuring the laser beam divergence allows you to create universal instrumentation-type instrumentation for measuring the beam divergence at various wavelengths and for various operating modes with low time spent on measurements needed to improve the qualities of the laser beam, and also allow time studies of the beam divergence based on which application is possible

divergence parameter in various automatic systems.

Subject invention

A method of measuring the beam divergence of an optical quantum generator, which includes focusing and splitting the beam under study into several beams, characterized in that, in order to shorten the measurement time and increase their accuracy, these beams pass through adjustable diaphragms, convert optical signals into electrical signals, direct Received signals to the recording and comparison system, where the ratios of the electrical signals of two measurements, taken at different diaphragm cross sections, are compared, where the divergence limit, e.g., by visually envelope amplitude pulse series.