Analysis of ultra-compact TE to TM polarization rotator in InGaAsP and SOI technologies

This article describes full analysis of a novel transverse electric (TE) to transverse magnetic (TM) polarization rotator based on mode interference utilizing finite element method. The core, substrate, and cladding of the polarization rotator are in the hybrid technology of InGaAsP and SiO2 materials. Effect of several parameters such as core's refractive index, width to height ratio of the polarization rotator, and incident light's wavelength on polarization conversion length, polarization efficiency, polarization extinction ratio, and rotation angle were investigated. Simulation results revealed that the rotation length was less than 1 μm, while the polarization conversion efficiency of 90%, polarization extinction ratio of 15 dB, and maximum rotation angle of 85° at 1.55 μm wavelength can be achieved.