水下成像光学系统设计1长春理工大学光电信息学院，吉林长春1300122中国中车长春轨道客车股份有限公司，吉林长春130062

在对目前水下成像系统现状进行调研后，分析了影响水下成像距离和成像质量的主要因素，即后向散射。突破了传统水下成像系统分视场、多探测器的成像方式，利用光学设计软件Zemax设计了一款大相对孔径、大视场的水下成像光学系统。系统只采用一个光电探测器，波长486 nm~656 nm，相对孔径1/1.8，视场角120°，采用9片透镜，无非球面，简化了透镜加工过程及成本。中心视场的艾里斑尺寸3 μm，在奈奎斯特频率60 lp/mm，时，各视场的调制传递函数曲线均高于0.7。同时，对大视场系统产生的高畸变进行校正，畸变小于5%，成像质量很好。此系统可广泛应用于水下探测、海洋开发、海底资源勘探、水下反恐等领域。

Design of underwater imaging optical system

After investigating the current status of underwater imaging system, the main factors affecting underwater imaging distance and quality were analyzed, namely backscattering.It breaks through the traditional imaging mode of underwater imaging system with multi-detector and multi-field of view.An underwater imaging optical system with large relative aperture and large field of view was designed by using optical design software Zemax.The system uses only one photoelectric detector with a wavelength of 486 nm~656 nm, a relative aperture of 1/1.8, a field of view angle of 1 200, 9 lenses and no aspheric surface, which simplifies the lens processing process and cost.The size of the Airyspot in the central field of view is 3.When Nyquist frequency is 60 lp/mm, the modulation transfer function (MTF) curves of each field of view are higher than 0.7. At the same time, the high distortion caused by the large field of view system was corrected, results show that the distortion is less than 5%, and the image quality is very good.It can be widely used in underwater exploration, marine development, seabed resources exploration, underwater anti-terrorism and other fields.