Hassan Shamsul, Chack Devendra, Mahajan Varad
Appl Opt. 2020 Apr 10;59(11):3369-3375. doi: 10.1364/AO.387418.
A polarization beam splitter (PBS) with a high extinction ratio that is based on multimode interference (MMI) is proposed and experimentally demonstrated on a silicon-on-insulator platform. The PBS is designed using cascaded MMI to enhance the extinction ratio (ER) and minimize insertion loss (IL) compared to a conventional MMI structure. The proposed device has a high extinction ratio (22.3 dB for TE and 25.6 dB for TM) and a low insertion loss (0.7 dB for TE and 0.1 dB for TM) at a wavelength of 1550 nm while the device supports a broad bandwidth of 60 nm (${\rm ER} \gt {16};{\rm dB}$ER>16dB) for both polarizations over a wavelength between 1520-1580 nm. Moreover, the eigenmode expansion method shows that the device has a large fabrication tolerance of an MMI width ${\pm} 40; {\rm nm}$±40nm and a length ${\pm} 1500; {\rm nm}$±1500nm. The proposed PBS can be used in on-chip silicon photonic integrated circuits for polarization division multiplexing.
提出了一种基于多模干涉（MMI）的具有高消光比的偏振分束器（PBS），并在绝缘体上硅平台上进行了实验验证。与传统的MMI结构相比，该PBS采用级联MMI进行设计，以提高消光比（ER）并最小化插入损耗（IL）。所提出的器件在1550 nm波长处具有高消光比（TE为22.3 dB，TM为25.6 dB）和低插入损耗（TE为0.7 dB，TM为0.1 dB），同时该器件在1520 - 1580 nm波长范围内对两种偏振态均支持60 nm的宽带宽（${\rm ER} \gt {16};{\rm dB}$）。此外，本征模展开方法表明，该器件对MMI宽度具有${\pm} 40; {\rm nm}$的大制造容差，对长度具有${\pm} 1500; {\rm nm}$的大制造容差。所提出的PBS可用于片上硅光子集成电路中的偏振分复用。
