Research and development of fiber-amplifier-integrated optical isolator

(1)光纤集成光隔离器我们制作了由法拉第旋转器、波长/2板和偏振分束器(金红石)组成的光隔离器芯片。采用TEC光纤实现光纤串联结构，以降低插入损耗。隔离度为45d B，插入损耗为3.5d B，反射衰减为47d B。该技术具有无透镜、无对准集成的特点，适合于光学器件的大规模集成。我们正在尝试用叠层偏振分束器取代金红石型光隔离器来实现高性能的光隔离器。(2)叠层偏振分束器由a-Si：H和SiO_2薄膜组成的叠层偏振分束器，得到了15.5ﾟ的分支角，与理论值基本一致。结果表明，插入损耗较大是由于各膜表面的粗糙度所致。我们用偏压溅射的方法使薄膜表面变平。用这种方法制作的LP对普通光束和特殊光束的损耗分别为0.16和0.17分贝。

(1)Fiber-integrated optical isolatorWe made an isolator chip composed of Faraday rotator, lambda/2 plate, and polarization splitter (rutile). Fiber-in-line structure was realized using TEC fiber, which was used for reducing the insertion loss. Isolation 45dB, insertion loss 3.5dB, and reflection attenuation 47dB were obtained. This technology leads to lens-free and alignment-free integration, so it is suitable for large-scale integration of optical devices.We are trying to realize a high performance optical isolator by replacing the rutile with the laminated polarization splitter.(2)Laminated polarization splitter (LPS)We made the LPS composed of a-Si : H and SiO_2 films and obtained the branching angle 15.5ﾟ, which is nearly equal to the theoretical value. It was found that the high insertion loss was due to roughness of each film surface. We flattened the film surface by bias sputtering. LPS, fabricated by this method, has losses of 0.16dB and 0.17dB for ordinary and extraordinary beam, respectively.