We report on the metal-organic chemical vapor deposition (MOCVD) of strained layer superlattices (SLSs) of InAsSb/InPSb as well as mid-infrared optically pumped lasers grown using a high-speed rotating disk reactor (RDR). The devices contain AlAsSb cladding layers and strained, type-I, InAsSb/InPSb active regions. By changing the layer thickness and composition of InAsSb/InPSb SLSs, we have prepared structures with low-temperature ( < 20 K) photoluminescence wavelengths ranging from 3.4 to 4.8 mu m. We find a variation in band gap of 0.272-0.324 eV for layer thicknesses of 9.0-18.2 nm From these data we have estimated a valence band offset for the InAsSb/InPSb interface of about 400 meV. The optical properties of the superlattices revealed an anomalous low-energy transition that can be assigned to an antimony-rich interfacial layer in the superlattice. An InAsSb/InPSb SLS, laser was grown on an InAs substrate with AlAs0.16Sb0.84 cladding layers. A lasing threshold and spectrally narrowed laser emission were seen from 80-200 K, the maximum temperature where lasing occurred. The temperature dependence of the SLS laser threshold is described by a characteristic temperature. T-0 = 72 K. from 80 to 200 K.