Optically pumped laser oscillation in the 1.6-1.8micron region from Al(0.4)Ga(0.6)Sb/GaSb/Al(0.4)Ga(0.6)Sb double heterostructures grown by molecular beam hetero-epitaxy on Si.

Double heterostructures consisting of GaSb active layers with Al(0.4)Ga(0.6)Sb cladding layers were grown by molecular beam hetero-epitaxy on Si substrates. The intrinsic ~12 percent lattice mismatch between the GaSb and the Si at the growth temperature is largely taken up by a GaSb/AlSb superlattice. The larger thermal contraction of the GaSb layer relative to that of Si causes the GaSb layer to be under severe dilatory strain relative to the Si substrate at room temperature. Optically pumped laser emission ranging from 1.62microns at 80K to 1. 82microns at 350K was observed. The threshold varied somewhat non-exponentially with temperature, with a change in slope at ~250K. The exponential threshold-temperature dependence at 80 and 300K are T(o) = 158 and 100K, respectively, and are higher than previously reported for GaSb lasers. At 300K the threshold corresponds to an effective current of 12 KA/cm(2).