Bichromatic Laser Doppler Velocity Vector Meter

Yu. N. Dubnishchev 1 2 3 * T. Ya. Dubnishcheva 4 V. G. Nechaev 2

1Institute of Thermophysics, Siberian Branch, Russian Academy Sciences, Novosibirsk, 630090 Russia

2Novosibirsk State Technical University, Novosibirsk, 630073 Russia

3Technological Design Institute of Scientific Instrument Engineering, Novosibirsk, 630058 Russia

4Novosibirsk State University of Economics and Management, Novosibirsk, 630099 Russia

Correspondence to: *e-mail: dubnistchev@itp.nsc.ru

June 4, 2020

Abstract—The article considers the possibility of constructing laser Doppler velocity vector meters based on a bichromatic source of spatially combined Gaussian or Bessel beams, the two-wave single-channel Bragg acousto-optic modulator with a ratio of ultrasonic wave frequencies equal to the ratio of the wave numbers of diffracted laser beams. The spatial, chromatic, and frequency structure of the 3D coordinate-measuring basis formed from the Gaussian or Bessel beams by the same sequence of optical elements and the photoelectric conversion adequate to the structure of light scattered by the investigated medium provide the minimum hardware Doppler spectrum width and increased noise immunity.

Keywords: bichromatic laser Doppler velocity vector metertwo-wave single-channel acousto-optic modulatorBessel laser Doppler anemometer

DOI: 10.3103/S8756699020040056