基于SU-8聚合物的越级衍射型单纤三向波分复用器

Ultra Compact Cross-Order Arrayed Waveguide Grating Triplexer Based on SU-8 Polymer

介绍了基于阵列波导光栅（AWG）的单纤三向波分复用器的设计、仿真、制作与测试。利用阵列波导光栅的频谱周期性，采用越级衍射方法可在无需改变AWG布局，无需额外元件的情况下覆盖三向波分复用器的整个工作波段（1310-1550 nm）。器件的芯层采用较高折射率的SU-8聚合物，下包层是二氧化硅，并用空气作为覆盖层，制作流程简单，只需要紫外光刻，成本低。仿真结果显示三个工作通道3 dB带宽都大于11 nm，偏振波长漂移不超过0.65 nm。器件测试结果验证了越级衍射设计的正确性，在TM偏振态下的第二和第三波长通道的额外损耗是3 dB左右，第一波长通道的额外损耗是7 dB左右，串扰在-15 dB左右。整个器件大小仅1.3 mm×0.402 mm。

A compact arrayed waveguide grating （AWG） triplexer based on SU-8 strip waveguides is designed and realized. The cross-order design method utilizing the spectral periodicity of AWG don′t need to change the layout of AWG, and there is no need of extra component to cover all three operating wavelengths of 1310 nm, 1490 nm and 1550 nm for the triplexer. The core layer is SU-8 polymer, the under-cladding is SiO2, and the upper-cladding is air. The AWG triplexer can be easily fabricated by using direct ultraviolet photolithography process without additional etching process. The simulation results show that the 3 dB bandwidth of three working channels are all larger than 11 nm, and the polarization dependence wavelength shift is less than 0.65 nm. Experimental results verify the cross-order design. For transverse magnetic （TM） polarization, the excess loss of the second and the third wavelength channel is about 3 dB, which is about 7 dB for the first. The crosstalk is better than -15 dB. The whole device has a compact size of as small as 1.3 mm×0.402 mm.