On-Chip Light Polarization Management by Mapping the Polarization Information to Phase Shift

Abstract

The comprehensive management of light polarization states has significantly advanced various fields into a new era. With the advent of photonic integration, there has been a persistent desire to replace the bulky optical components with compact chip-scale circuits. Nonetheless, the complete integration of polarization-dependent systems has not yet been accomplished due to the absence of a mature polarization management scheme that possesses a tiny form factor and high foundry process compatibility meanwhile maintaining low operation complexity. Here, to overcome these limitations a novel concept called polarization phase mapping, which encodes the information between the light polarization in one waveguide and the relative light phase shift in another two waveguides, is proposed. With this bi-directional mapping approach, the fundamental basis of polarization management has shifted from polarization adjustment to phase regulation. All essential polarization-related functions including synthesizing, stabilizing, measuring, rotating, splitting, and mixing are demonstrated with the standard process in foundries. The size of the polarization rotating unit is pushed down to a few light wavelengths while keeping a competitive performance. Moreover, the proposed concept can be readily applied to other integrated photonics platforms. It is expected to unlock new opportunities for complex polarization-related applications.