Demonstration of a 256×256 middle-wavelength infrared focal plane array based on InGaAs/InGaP quantum dot infrared photodetectors

We report a demonstration of an infrared focal plane array based on InGaAs/InGaP quantum dot infrared photodetectors. The middle-wavelength infrared quantum-dot infrared photodetector (QDIP) structure was grown via low-pressure metal organic chemical vapor deposition. A detectivity of 3.6×1010 cm Hz1/2/W was achieved at T=95 K and a bias of −1.4 V. The background limited temperature of our QDIP was 140 K with a 45° field of view. A 256×256 detector array was fabricated with dry etching, and hybridized to a Litton readout chip by indium bumps. Thermal imaging was achieved at temperatures up to 120 K. At T=77 K, the noise equivalent temperature difference was measured as 0.509 K with a 300 K background and f/2.3 optics.