光通信中天线表面颗粒沾染与激光波长的关系  

Relationship between Antenna Contamination and Laser Wavelength in Optical Communication

作　　者：乌大琨[1,2] 周彦平[1] 

机构地区：[1]哈尔滨工业大学航天学院,黑龙江哈尔滨150041 [2]哈尔滨工业大学物理系,黑龙江哈尔滨150001

出　　处：《中国激光》2009年第3期564-568,共5页Chinese Journal of Lasers

摘　　要：空间光通信系统天线表面的颗粒沾染能够导致光通信系统光学性能的变化。利用时域有限差分法(FDTD)建立了空间光通信系统天线表面沾染模型,考虑到空间光通信远场发射、远场接收的特点,在直接利用FDTD法得到近场光强分布的基础上,进行了近场一远场变换。实例计算表明,对于一定直径的微粒,当颗粒间距达到某一值时,近场光强分布为具有一定数值的直线。然后以此光强分布为参考,计算了微粒直径相同、入射波长不同时所对应的颗粒间距最大值。结果表明,r■λ时,波长越长,对应的颗粒间距越大。在进行空间光通信系统的防护设计时,如果载波波长较长,应尽量减少光学表面大颗粒的形成。Surface-deposited particles can impact on the optical performance of space optical communication. A model of antenna surface contamination is set up by finite-difference time-domain(FDTD) method. Transformation from near field to far field is made, basing on the near-field light intensity distribution calculated by FDTD for emission and receiving are all from far field. It is remarkable that distribution of near-field transmitted light intensity reaches a certain value, when distance between certain radius particles reaches a value, and the distribution is regarded as a reference. The relevant maximum distance between particles is obtained, with the same particles size and different wavelength. The results show that for a certain distribution of light intensity, the longer the laser wavelength is, the greater the relevant distance between particles is on the condition that the particle size is much larger than the wavelength. While designing the defence of space optical system, the big particles forming on the optical surface should be reduced for longer carrier wavelength.

关 键 词：光通信 光强分布 时域有限差分法 颗粒沾染 

分 类 号：V443+.1[航空宇航科学与技术—飞行器设计] TN929.12[电子电信—通信与信息系统]