Design Of Aspheric Optical System In Transceiver For Ultraviolet Free-space Communication Near Surface Layer

Ultraviolet free-space optical communication near surface layer is a new secure communication model based on atmospheric absorption and scattering which is able to achieves non line-of-sight communication in a complicated environment. Due to its advantages such as low interception rate,low identification rate,anti-interference, omnidirectional, non line-of-sight, all-weather work,and no ATP. It is an ideal way to meet the requirements of tactical communication, as result, gain more and more attention from the national military.As one of the key component of ultraviolet free-space optical communication near surface layer,the optical system is helpful to improve the ability of collecting the weak signal from the atmosphere, and the receiver sensitivity and efficiency of the detection signal for the ultraviolet communication system. This subject studies the ultraviolet free space optical communication system design based on the analysis of the ultraviolet free space communication system present situation and development trend at home and abroad.Firstly,this paper expounds the basic working principle of the ultraviolet communication system and ultraviolet communication the optical system. According to the characteristics of the ultraviolet communication system of communication, the design of optical system of ultraviolet communication theory is analysed,including ultraviolet radiation on the transmission characteristics of the atmosphere, the influence of the optical system parameters on the transmission performance of ultraviolet communication. The related devices of the ultraviolet communication such as the UV source, the UV detector,and the materials of the optical system is chosen in order to meet the requirements of indicators. The telephoto optical system structure is analyzed and optical optimization function in the optical design software is studied. And the theory for aspheric surface is discussed.Secondly,the optical structure and transceiver structure is analyzed, and the catadioptric optical system is chosen as the initial structure of receiving optical system, Galileo refraction system is the initial launch of optical system structure, transceiver structure of UV communication optical system is adopted coaxial type according to the performance requirements.Finally,the concept for designing the optical system and the system function and technical index,in accordance with requirements of the system indicators is put forward. The paper selects the initial structure of the optical system in transceiver and puts forward the design method and technical parameters to obtain the initial structure parameters of the system. An ultraviolet communication optical system in transceiver is designed by Zemax. The field of view(FOV) of receiving optical system of is 360 ° x(5 ° ~ 20 °) and the beam expanded ratio of launching optical systems is 5. It is concluded that the specific implementation results for engineering is designed. The optical system is optimized and the design result(tolerance) is analyzed and discussed according to the requirement of the ultraviolet communication system.Results show that the design of ultraviolet communication optical system is in transceiver structure. The receiving optical system has a larger FOV. The structure of the optical system is simple and easy to manufacture. The optical system meets the properties including small and portable,which lay the foundation for the practical ultraviolet communication.