Dual-color detection using two quasi-bound states in the continuum in an InGaAs/InAlAs superlattice

A voltage-tunable mid-infrared dual-color quantum Bragg mirror detector (QBMD) is presented. The dual-color was achieved by using two quasi-bound states in the continuum (leaky electronic states) and exploring the heterostructure asymmetry to generate leaky states with preferential directions for the electronic extraction. In photovoltaic mode, the photocurrent spectrum presents a positive peak at 340 meV and a negative one around 430 meV. Dual-color detection can be turned into single-color detection (positive or negative peak) when an external bias voltage is applied.