A novel device for detecting the polarization direction of linear polarized light using integrated subwavelength gratings and photodetectors

A solid-state device that can be used to detect the polarization direction of linear polarized light is proposed. The device consists of six transmission gratings with periods in the subwavelength region of the incident light and six photodetectors integrated separately underneath each grating. A variable, defined through the photocurrent ratios of the grating-photodetector pairs, shows a one-to one correspondence with the angle between the electric vector of the incident linear polarized light and the orientation of the gratings' fingers, which is therefore used to determine the polarization direction. An angular resolution of 0.2/spl deg/ can be achieved.