Ultra-Compact Active TE and TM Pass Polarizers Based on Ge2Sb2Te5 in Silicon Waveguide

Active transverse electric and transverse magnetic-pass polarizers with only 1 μm length based on Ge2Sb2Te5(GST) silicon waveguides are theoretically demonstrated. The tunability of both polarizers relies on the phase change of GST. The analysis predicts that both devices exhibit insertion losses (ILs) below 0.8 dB in an amorphous phase. With the change to the crystalline phase, the undesired polarization is attenuated above 18.2 dB, whereas ILs are maintained below 0.8 dB (TM pass) and 2.6 dB (TE pass) at a center wavelength of 1550 nm. The operation bandwidth over a range of 100 nm is also achieved.