中文摘要：

在基于偏振编码的光通信试验中,需要对不同波长的线偏光进行光路分离,同时要保持分离后线偏光的偏振方向和消光比,为此设计和制备了入射角为45°的810 nm波长透射/850 nm波长反射的近红外分色片.为了抑制斜入射条件下工作波长附近s、p偏振分量的能量、相位分离,选择了合适的基础膜系,利用旁反射带边缘透、反射带光谱过渡迅速的特性,实现了临近波长的光路分离,也减小了偏振分离;通过非规整膜层的相位补偿和软件自动优化,实现了设计目标.分别选用TiO2和SiO2为高低折射率膜层材料,以离子束辅助沉积技术镀制薄膜,采用光学极值法和晶体振荡法结合的方式控制膜层厚度.制备样品的消光比在波长810 nm处达到7000∶1以上,在850 nm处达到20000∶1,实现了分色片对相位的控制,满足了偏振编码光通信试验的需求.

英文摘要：

To separate two polarized lights with wavelengths at 810 nm and 850 nm,respectively,into two optical beams while keeping their polarization directions unchanged and degree of polarization maximized,a dichroic beam-splitter at incidence angle of 45°was designed and fabricated.The 810nm beam passes through the splitter while 850nm beam is reflected.An apposite initial film configuration was selected to control the separation of s-and p-polarization components.It was further optimized with the Global Modified LM method in Film Wizard software.The phase and energy parameters of the seperated two beams meet the design target.TiO2 and SiO2 have been chosen as high-and low-refractive index layer materials,respectively.Ion beam-assisted deposition,optical extreme value method,and quartz crystal oscillator have been used to control the thickness of films.The extinction ratio of obtained sample reaches 7000 ∶1 in 810 nm beam and 20000 ∶1 in 850 nm beam.The control of phase and energy of optical thin films were realized to meet the demands of polarization state coding for its application in communication.