Optical Design Of Long-wave Infrared Imaging System For Mobile Devices

Long-wave infrared optical lens as a key component of infrared detection device bears the responsibility of focusing the infrared signal to detector.The ability of its imaging function,to a certain extent,determines the overall performance of infrared device.At present,attributed to the outstanding contribution long-wave infrared detectors made in low cost and integration,the traditional long-wave infrared device has been widely used in military,industrial and medical fields.But in the civilian area,especially consumer electronics market,it is still not being expanded.Besides the cost of detector itself,the high cost of infrared optical lens also constraints it away from the civilian application.Therefore,it is of great meaning to study the design of low-cost compact mobile long-wave infrared optical system.The work of this topic is mainly simulated by Zemax software.Based on the related optical design theory,the long-wave infrared optical lens is designed with low cost,small volume and high performance.This article contains of the following aspects:(1)The traditional long-wave infrared optical system has been designed,based on two lenses made by germanium material.The two lenses structure only using one aspheric surface and the aberration has been optimized well.The imaging result is close to the diffraction limit.(2)The traditional long-wave infrared optical system has been extended in function,and the dual-band visible/long-wave infrared optical system has been designed.To solve the problems of material selection and volume control,through analyzing the achromatic theory,we choose KBr-ZnS as the achromaticity material for aberration correction and use refraction structure to avoid large volume and block problem brought by former structures.The new design ensures to fit the mobile application.(3)Designing the long-wave infrared single-lens optical system with a Fresnel surface and an aspheric surface.Compared with the traditional multi-lens imaging system,the cost of the lens is reduced while the image quality is not significantly affected.