Fully integrated CMOS-compatible polarization analyzer

Abstract

Polarization measurement has been widely used in material characterization, medical diagnosis and remote sensing. However, existing commercial polarization analyzers are either bulky schemes or operate in non-real time. Recently, various polarization analyzers have been reported using metal metasurface structures, which require elaborate fabrication and additional detection devices. In this paper, a compact and fully integrated silicon polarization analyzer with a photonic crystal-like metastructure for polarization manipulation and four subsequent on-chip photodetectors for light-current conversion is proposed and demonstrated. The input polarization state can be retrieved instantly by calculating four output photocurrents. The proposed polarization analyzer is complementary metal oxide semiconductor-compatible, making it possible for mass production and easy integration with other silicon-based devices monolithically. Experimental verification is also performed for comparison with a commercial polarization analyzer, and deviations of the measured polarization angle are <±1.2%.