Wang Yu, Calabretta Nicola
Opt Lett. 2022 Oct 15;47(20):5268-5271. doi: 10.1364/OL.470802.
We present and numerically demonstrate a novel polarization-insensitive (PI) 40-channel 100-GHz spacing fold-back planar echelle grating (PEG) multiplexer/demultiplexer (Mux/Demux) to realize the compact 1 × 2 crossing-less photonic integrated wavelength-selective switch (PIC-WSS). The PI operation is achieved by a polarization splitter to feed the TE and TM mode into the PEG via two waveguides with different incidental angles so that the two diffracted modes combine at the same output waveguide. By optimizing the design of different input/output angle combinations and sharing the same blazed angle, a single compact PI PEG with fold-back configuration can simultaneously work as twice the Demux and Mux required. The footprint of the single fold-back PI PEG is only ∼40 mm. The numerical results show that the 40-channel 100-GHz spaced PI fold-back PEG has < 2.4 dB insertion loss, < -60 dB cross talk, zero polarization-dependent wavelength shift (PDWS), 0.3 dB polarization-dependent loss (PDL), < 0.5 dB loss variation and < 0.01 nm wavelength shift between Mux and Demux.
我们展示并通过数值验证了一种新型的偏振不敏感（PI）40通道、100GHz间距折返式平面闪耀光栅（PEG）复用器/解复用器（Mux/Demux），以实现紧凑的1×2无交叉光子集成波长选择开关（PIC-WSS）。通过偏振分束器将TE和TM模式通过两个具有不同入射角的波导馈入PEG来实现PI操作，从而使两个衍射模式在同一输出波导中合并。通过优化不同输入/输出角度组合的设计并共享相同的闪耀角，具有折返配置的单个紧凑PI PEG可以同时作为所需的解复用器和复用器的两倍工作。单个折返式PI PEG的占地面积仅约40mm。数值结果表明，40通道、100GHz间距的PI折返式PEG具有<2.4dB的插入损耗、<-60dB的串扰、零偏振相关波长偏移（PDWS）、0.3dB的偏振相关损耗（PDL）、<0.5dB的损耗变化以及复用器和解复用器之间<0.01nm的波长偏移。
