Phase shift measurement of optical noise waveform modulation envelope

Abstract

The paper presents investigation results of a single-beam anemometer, in which the only one optical beam is used. The principle of operation of single-beam anemometer is based on the fact that the frequency shift due to Doppler effect appears both on a carrier frequency (optical band) and on the frequency of any oscillation, which can be distinguished from the signal by means of linear or nonlinear transformations. Such system is less dependent on destabilizing factors such as temperature fluctuations, mechanical impact of system components, vibration, etc. The extraction of information from the modulating signal, but not directly from the signal of the optical range allows using slow-speed and therefore less expensive components(photodetectors, ADC’s). The approach used in the work ultimately simplifies the measuring device and makes it more reliable.