Design and fabrication of an InGaAs focal plane array integrated with linear-array polarization grating.

Polarization imaging plays a crucial role in modern photonic applications such as remote sensing, material classification, and reconnaissance. A novel InGaAs focal plane array integrated with linear-array polarization grating is proposed and fabricated to meet the practical needs of near-infrared polarization imaging. In order to accurately evaluate the polarization performance of a fabricated detector, the improved test system is used to measure the transmittance and extinction ratio (ER). The results show that the detectivity reaches ${1}.{06}\; \times \;{{10}^{12}}\;{{\rm cm}\cdot{\rm Hz}^{1/2}}/{\rm W}$1.06×1012cm⋅Hz1/2/W, and the operable pixel factor is more than 99.8%. The transmittance of more than 55% and the ER of greater than 21:1 are realized, which indicates that the fabricated detector has excellent capability for near-infrared polarization imaging.