Thermal analysis of TeO2-based acousto-optic tunable filters for spectral imaging

AOTF (Acousto-Optic Tunable Filter) spectral imaging devices is widely utilized in remote sensing applications due to its advantages of no moving parts, rapid response, and robust reliability. TeO2 (Tellurium dioxide)-based AOTF, currently represent as the most commonly employed acousto-optic crystals owing to TeO2 excellent acousto-optic figures of merit. The effect of heat in acousto-optic devices is a persistent problem because acousto-optic interactions necessitate maintaining a specific acoustic power within the crystal. Various efforts have been applied to analyze and obtain the temperature field of acousto-optic devices. Various efforts have been applied to measurement of the temperature distribution of AOTF devices. However, there is still lack the research of accurate thermal modeling for AOTF devices. This paper presents a thermodynamic model based on finite element-based approach to simulated the thermal characteristics of AOTF device. Approach considerations include the impact of device impedance matching on actual electrical power consumption, as well as factors like acoustic anisotropy and the heating effect of the acoustic absorber. Simulation model conducted on the entire device, encompassing the shell. Experimental validation was carried out by measuring the surface temperature of AO crystals under various thermodynamic conditions.