Spatial-Dynamic Characteristics Research of a Laser Beam at Interacting with Thermal Convection Flow

In this paper the results of experimental research of the dynamics of changes in the spatial and dynamic characteristics of a laser beam during spreading in a thermal convection flow area are showed. The appearance of thermal convective flow leads to random changes in the refractive index of the area. Thus, at spreading in such area, the profile of the laser beam intensity distribution will fluctuate. Which can be registered by appropriate mathematical processing. The structural scheme of the system for detection of thermal convective flow is developed. The developed system is based on registration of fluctuations allocation of laser beam intensity profile. The system and experiments on simulation of the normal operation mode and registration of the thermal convective flow appearance are given. An integral-difference method of beam profile processing, reflecting the pixel-by-pixel difference of beam intensity profile distribution counts are proposed. The efficiency of the correlation and integral-difference methods of processing the spatial characteristics of the beam profile are researched and compared. Computer processing and graphical dependences of the obtained data on the dynamics of changes in the beam intensity profile distribution was carried out. Which shows the beginning of the thermal convective flux in the experiment.