Efficient and compact TE–TM polarization converter built on silicon-on-insulator platform with a simple fabrication process

An efficient TE–TM polarization converter built on a silicon-on-insulator nanophotonic platform is demonstrated. The strong cross-polarization coupling effect in air-cladded photonic-wire waveguides is employed to realize the conversion. A peak TE–TM coupling efficiency of 87% (−0.6?dB insertion loss) is measured experimentally. A polarization conversion efficiency of >92% with an overall insertion loss of <−1.6?dB is obtained in a wavelength range of 40?nm. The proposed device is compact, with a total length of 44?μm and can be fabricated with one lithography and etching step.