Dilute-nitride InAs bulk materials with up to 2.25% of nitrogen were grown by molecular beam epitaxy on InAs substrates. Photoluminescence (PL) and optical absorption measurements demonstrate a bandgap reduction by up to 150 meV with increasing nitrogen incorporation. Close correspondence of the energies of the photoluminescence peak and absorption edges indicate limited Moss-Burstein shift. Minority carrier lifetimes in the nanosecond range are measured using an ultra-fast PL up-conversion technique for the samples with up to 2% of nitrogen. Orders of magnitude advance of the carrier relaxation lifetimes as compared to GaSbN encourage development of the InAsN as a potential material for mid-IR detector applications. (C) 2010 Elsevier B.V. All rights reserved.