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

Abstract

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 ${\text{3.6×10}}^{10}\hspace{0.5em}{\mathrm{cm Hz}}^{\text{1/2}}/\mathrm{W}$ was achieved at $\text{T=95\hspace{0.5em}}\mathrm{K}$ 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 $\text{T=77\hspace{0.5em}}\mathrm{K},$ the noise equivalent temperature difference was measured as 0.509 K with a 300 K background and $\text{f/2.3}$ optics.