An on-chip full-Stokes polarimeter based on optoelectronic polarization eigenvectors

Abstract

Determining the polarization state of light is important in a variety of applications from optical communication to biomedical diagnostics. Polarimeters are, however, typically based on discrete bulky optical components, which can restrict miniaturization and limit wider application. Here we report the concept of an optoelectronic polarization eigenvector, which represents the linear relationship between the incident Stokes vector and the photocurrent of a detector. By configuring four of these eigenvectors to create an optimized optoelectronic conversion matrix, we establish a high-accuracy full-Stokes polarization detection method and use the approach to create a compact on-chip full-Stokes polarimeter. The polarimeter comprises four subpixels that share the same piece of few-layer molybdenum disulfide as the detection material. Each subpixel contains an integrated plasmonic metasurface and corresponds to a distinct optoelectronic polarization eigenvector. By tailoring the plasmonic metasurfaces and their geometric arrangement, the condition number of the optoelectronic conversion matrix can be minimized to achieve high-accuracy Stokes reconstruction. Using an optimized matrix, combined with a machine learning algorithm, the root mean square error of the full-Stokes reconstruction over the entire range of polarization states at arbitrary light intensities is less than 1%. Using a framework based on optoelectronic polarization eigenvectors and optoelectronic conversion matrixes, an on-chip full-Stokes polarimeter can be created that offers a root mean square error of less than 1% for each Stokes parameter over the entire range of polarization states at arbitrary light intensities.