Reconfigurable and low-power consumption polarization rotating beam splitter with EIT-like effect based on SOI ridge waveguide

Abstract

Polarization rotating beam splitter (PSR) is a key component of an on-chip polarization diversity system. However, a conventional PSR is usually designed for a specific use case, which limits general-purpose applications since its polarization rotation and beam splitting ratio are fixed. In this paper, this theoretical modeling, numerical simulations, and experimental results on the reconfigurable PSR with arbitrary beam splitting ratio is proposed for the silicon on insulator (SOI) platform. The device includes a polarization rotation region and a beam splitting region. The polarization rotation region is composed of multi-segment tapered waveguides, and the beam splitting region consists of a racetrack resonator with a heater. By changing the voltage applied to the heater, the beam splitting ratio can be changed. Measured results show that when the incident light is TM0 mode, it will be converted to TE0 mode and output from two output ports. The beam splitting ratio of the two output ports can be adjusted from 9:1 to 1:9. Furthermore, in order to optimize the thermal tunability of the PSR, we introduce an asymmetric embedded racetrack resonator with electromagnetically induced transparency (EIT)- like effect in beam splitting region, which can reduce the power consumption dramatically from 27.5 mW to 1.8 mW. The proposed integrated PSR suggests great potential for reconfigurable, fully programmable photonic polarization diversity circuits. In addition, we believe such an embedded racetrack resonator with EIT-like effect could find its applications in chip-scale sensor, modulator, switch, etc.