Highly-efficient broadband TE/TM polarization beam splitter.

Highly-efficient broadband polarization beam splitters with small footprint and based on silicon photonics technology are of great importance in optical integrated circuits. In this paper, a crucially applicable optical component of a TE/TM polarization beam splitter has been designed and simulated using the inverse design of adjoint method. The mentioned device has ultra-high transmission efficiency (about 96% for TM$_{00}$ and 93% for TE$_{00}$ modes) and high extinction ratio of more than 16 dB over the bandwidth of 200 nm. Small footprint (2.2 $\times$ 2.1 $\mu$m$^2$), broad bandwidth (200 nm), and compatibility with CMOS technology fabrication indicate the eligibility of this device.