一种实用的准单色光退偏器的研究

Binary Microlenses Used in High Density Wavelength Division Multiplexer

用矩阵方法对一种准单色光退偏器Ｌｙｏｔ改进型退偏器进行了详细的理论分析，得到了该退偏器的有效退偏条件为：１）退偏器的总延迟必须足够大；２）晶体楔角或通光孔径必须足够大；３）二晶体光轴夹角必须是４５°。实验表明，该退偏器在４００～８００ｎｍ宽光谱范围内对±１０ｎｍ的任意准单色偏振光进行退偏后，平均的残余偏振度小于１．２％。

Using phase balance design method and the accumulating integral method, the Binary Optical Microlenses (BOML) is designed and used in high density grating wavelength division multiplexers with the working wavelength of 1.536￣1.564 μm and the channel spacing of 4 nm. The phase structure of the binary optical microlenses and the diffraction far field distribution at the end of the receiving fibers are calculated. The loss resulted from the microlenses when the single mode and the multi mode receiving fiber are used, and the ratio of the fundamental modes excited in the multi mode receiving fiber for eight channels are discussed.