Opto-electrical and polarization performance of a mesa-structured InGaAs PIN detector integrated with subwavelength aluminum gratings

Polarization detection in the short-wave infrared (SWIR) region presents broad applications in clinical medicine, sensing, surface reconstruction, etc. A mesa structure can prevent light crosstalk due to its intrinsic advantage, making it potentially suited to meet the need for manufacturing smaller-sized devices to save cost and shrink volume. In this paper, the mesa-structured InGaAs PIN detector with the spectral response ranging from 800nm to 1700nm and the detectivity of 6.28×1011 cm·Hz1/2/W at 1550 nm and -0.1 V bias (room temperature) has been demonstrated. Furthermore, the devices with four orientations subwavelength gratings show obvious polarization performance. The extinction ratios can reach 18:1 at 1550 nm and the transmittances are over 90%, respectively. Such a polarized device with mesa structure could be a strategy for the realization of small-sized SWIR polarization detection.