Realizing the High Efficiency of Type-II Superlattice Infrared Sensors Integrated Wire-Grid Polarizer via Femtosecond Laser Polishing

Abstract

A comprehensive strategy to enhance the polarization performance of mid-wave infrared photodetectors (PDs) is developed and implemented by integrating wire-grid polarizers (WGPs) using nanoimprint lithography and femtosecond laser (FSL) polishing. This combined approach offers significant advantages, including large-area fabrication capabilities, practical device integration, and improved polarization characteristics. By addressing optical losses, the primary factor contributing to polarization degradation through the thermal effects of FSL polishing, substantial improvements are achieved in surface roughness and grain boundary reduction on the WGP, resulting in remarkable performance enhancements. As a result, the extinction ratio of the integrated WGP InAs/GaSb type-II superlattice PD achieves an impressive value of up to 1044. This approach holds promising potential for advancing polarization-based imaging and measurement systems to new heights.