Optical Design And Stray Light Analysis Of Active Laser-guided Seeker

As a type of precision-guided weapon, the laser-guided weapon has the advantages of high hit accuracy, strong anti-interference ability, low cost and easy to use. It has been widely used in the local war in recent years and played a significant role in the war, thus has become the research focus of many military power.In order to realize true disregard of missile after launching and improve the operational effectiveness and viability, developing full-active laser guidance system with low cost, high efficiency and high guidance accuracy becomes the main trend of the development of the laser guidance system in the future.Seeker optical system is the core component of laser guidance system, therefore, the development of active laser emitting and receiving guidance system is the key to achieve fully active laser guidance. In this paper, a novel fiber laser is adopted as laser source and the dual-wedged scanning system is applied to an innovative laser-guided seeker optical system. The common path design of laser transmitting and receiving system is achieved and implemented, which can realize fully automatic detection and tracking of target after the laser-guided weapons is launched.The main research works of this paper are as follows:1. The characteristics of the dual-wedged scanning system is studied, then a new type of high-precision scanning device with advantages of simple framework, high accuracy and fast scanning speed is designed according to the demands of fully automatic laser-guided system.2. R-C catadioptric collimated beam expander and focusing lens group is designed to achieve the common path design of laser transmitting and receiving system. The laser transmitting light path is comprised of collimated beam expander and scanning unit, it can reduce the divergence angle of transmitting laser beam, enhance the resolution of system objective and detection range and achieve the collimating emission of laser beam and fast scanning of objectives. The diffuse reflection of laser echo wave is received by R-C catadioptric collimated beam expander, scanning unit and focusing lens group, and is focused onto the detector.3. The stray light of fully automatic laser-guided seeker system’s structure is analysed. First, the internal baffle, outer baffle and its vane of R-C catadioptric system is designed according to the properties of the optical system of the seeker. Then hybrid optical analysis software-Lighttools is used to model the opto-mechanical structure. The stray light transmission path of the optical system is analyzed and its capacity of eliminating stray light is evaluated.