Quantum Dots-Based All-Optical-Readout Middle-Far-Infrared Imaging

A quantum dot (QD) middle-far-infrared (MFIR) detection and imaging approach based on all-optical-readout (AORO) is proposed. Using the intersubband (ISB) optical transition to change the interband (IB) absorption, it converts the ISB MFIR signal into the IB near-infrared signal. It might overcome the problems in the electrical readout infrared detection and imaging, such as dark current, low-temperature operation, low resolution, and vulnerability to the high radiation intensity. Based on the In_0.5Ga_0.5As/GaAs lens-shaped QD structure, our calculation shows the potential of this AORO approach for the MFIR detection and high-resolution imaging, the potential for room-temperature operation, and the ability for frequency selectivity and spectrum scanning.