Summary form only given. The InAsSb/AlSbAs heterojunction system is promising for mid-infrared (2-5 μm) lasers, since it combines the narrow band gap of an InAsSb alloy (< 0.4 eV at 77K) with a large conduction band offset at the hetero-boundary. The use of a strained quantum well (QW) active layer instead of thick InAsSb one is believed to increase the differential gain and reduce considerably the Auger recombination which limits the maximum operating temperature of such lasers. We report on MBE growth and photoluminescence (PL) properties of compressively strained InAsSb/AlSbAs single QW heterostructures. A set of norminally-undoped structures with well widths varying from 4 to 20 nm was grown pseudomorphically on GaSb [001] substrates using a two-stage growth regime. PL measurements of the structures were performed at 80K. Temperature and pump-power dependences of the PL intensities versus various structure parameters will be discussed.