On-chip Stokes Polarimeter Based on a Two-dimensional Grating

Polarization is one of the fundamental physical quantities of light and has been applied in many fields. Traditional bulky polarimeters have a large size and the reported chip-scale polarimeters usually need rigid parameter design. Here, we propose an on-chip Stokes polarimeter based on a two-dimensional grating with loose constraints. The two-dimensional grating splits the x and y polarization components of incident light to four separate branches, then recombined into four new channels to get different polarization information. The Stokes parameters of input light can be retrieved according to the inherent output power matrix of new channels. The measured root mean squared errors of ellipticity angle and orientation angle are 1.82 degree and 2.33 degree respectively. Our work provides an on-chip polarimeter solution with a large fabrication tolerance.