Stimulated emission at 5.1 mu m was demonstrated from a broad area In1
-xAlxSb/InSb heterostructure diode laser grown by molecular beam epita
xy. For a 5 mu s pulse and a 500 Hz repetition rate the threshold curr
ent density was 1480 A cm(-2) at 77 K and the maximum operating temper
ature was 90 K at a current density of 2680 A cm(-2). Maximum peak pow
er output was estimated to be 28 mW per facet at 77 K and 4500 A cm(-2
).