Capabilities of AlN/SiC adaptive optics for unmanned rescue vehicle applications

Ioffe Institute, 194021 Saint Petersburg, Russia

^* Corresponding author: Eugeny.Panyutin@mail.ioffe.ru

Abstract

The possibility of using epitaxial AlN/SiC structures with technologically conditioned surface curvature as electrically controlled adaptive lenses for high-temperature applications, in particular, to equip image sensors for unmanned rescue vehicles operating in fires is discussed. Advances in epitaxial III-nitride technology for "thick" AlN-layers and multilayer heterostructures lead to a new approach to the development of electrically steerable lenses based on the inverse piezo effect oriented toward the optical axis. In contrast to the radially oriented piezo effect previously used to produce bending deformations in bimorph membrane-type microlenses, this design approach will improve the mechanical strength and reliability of the lens and is expected to produce adaptive thermal compensation of its optical parameters for possible changes of the ambient temperature in a wide range (up to 1000ºC). Within the framework of this concept an algorithm has been developed and modelling has been carried out to calculate the optimum value of the control voltage as a function of temperature for various values of the curvature radius of the AlN/SiC heterogeneity.