Progress towards intersubband quantum-box lasers for highly efficient continuous wave operation in the mid-infrared

摘要

Intersubband quantum-box (IQB) lasers, which are devices consisting of 2-D arrays of ministacks (i.e., 2-4 stages) intersubband QB emitters have been proposed as alternatives to 30-stage quantum-cascade (QC) devices, for efficient room-temperature (RT) emission in the mid-infrared (4-6 (mu)m) wavelength range. Preliminary results include: 1) the design of devices for operation with 50percent wallplug efficiency at RT; 2) realization of a novel type of QC device: the deep-well (DW) QC laser, that has demonstrated at lambda velence 4.7 (mu)m low temperature sensitivity of the threshold current, a clear indication of suppressed carrier leakage; 3) the formation of 2-D arrays at nanopoles by employing nanopatterning and dry etching; 4) the formation of 40 nm-diameter, one-stage IQB structures on 100 nm centers by preferential regrowth via metal-organic vapor phase epitaxy (MOVPE).