Photonic Polarization Rotator Research Articles

Efficient, compact, and robust GeOI-based photonic polarization rotator in the 2 [formula omitted]m waveband

Based on the germanium-on-insulator (GeOI) platform, we numerically demonstrate a photonic polarization rotator (PR) operating in the 2 μm waveband. Utilizing the partial-height etching to break the symmetry of germanium waveguide cross section, the proposed PR realizes a 90° polarization rotation between the fundamental transverse electric (TE) and magnetic (TM) modes. The device footprint occupies only 0.4 μm ×0.4μm ×3μm. This PR shows a low insertion loss of 0.096 dB, a remarkably high polarization conversion efficiency (PCE) of 98.9%, and an extremely high extinction ratio of 33.45 dB at the wavelength of 2005 nm The PCE keeps above 95.4% within the waveband between 1.9 μm and 2.1 μm. Furthermore, a reasonable robustness is demonstrated.