  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.
