Demonstration of the Very Long Wavelength Infrared Type-II Superlattice InAs/InAsSb GaAs Immersed Photodetector Operating at Thermoelectric Cooling

In this letter, we report on the InAs/InAsSb type-II superlattice (T2SL) detector operating with 50% cut-off wavelength ( \lambda _{\mathbf {c}})~\sim ~15~\mu \text{m} for temperatures ( T ) reached by three-stage thermoelectric (TE) cooling to minimize the detector's volume to reach size, weight, and power (SWaP) conditions. The presented device reaches detectivity (D *) ~ 10 9 Jones ( \lambda _{\mathrm {c}}\sim ~15~\mu \text{m} ). These results are the first reported on single pixel T2SL InAs/InAsSb photoconductor with \lambda _{\mathrm {c}}\sim ~15~\mu \text{m} where GaAs immersion lens (IL) was implemented and integrated with three-stage Peltier TE cooler.