A voltage-tunable multi-spectral 320x256 InAs/GaAs quantum-dot infrared focal plane array (FPA)

A voltage-tunable multispectral 320×256 infrared imaging focal plane array (FPA) is reported. The multispectral FPA is based on InAs/GaAs quantum dots infrared photodetectors (QDIP) with different capping layers (i.e. GaAs and In_0.20Ga_0.80As), corresponding to the extended middle-wave infrared (EMIR, 5-8 μm) and long-wave infrared (LWIR, 8- 12 μm) detection bands, respectively. The FPA shows a sensitivity of 8.2 mV/C a noise equivalent temperature difference of 172 mK at the FPA operating temperature of 67 K. Thermal images were obtained at both the EMIR and the LWIR bands at a low FPA bias of -0.7V. Voltage-tunable multispectral imaging was also achieved. Since each of the detection spectral of the QD FPA can be individually tuned by engineering its QD capping layer, this approach offers greater flexibility in designing detection spectrum of a multispectral FPA.