High-Power 2.2-$\mu$m Diode Lasers With Metamorphic Arsenic-Free Heterostructures

Metamorphic virtual substrates with lattice constants 0.9% larger than those of GaSb were developed by solid-source molecular beam epitaxy. The mismatch between the parent GaSb and the virtual substrate was accommodated by a network of misfit dislocations formed in GaInSb buffer layers with linearly graded indium and gallium compositions. Arsenic-free laser heterostructures emitting at 2.2 μm at room temperature were grown on virtual substrates. The antimony was the only group V element used in growth. These novel diode lasers operate at room temperature and generate above 1.4 W of continuous-wave (CW) power.