Broadened-waveguide W quantum-well diode lasers operating at λ=3.2 μm

We report a demonstration of non-cascade electrically pumped mid-IR lasers employing W active wells in conjunction with broadened-waveguide separate-confinement regions. Lasers were grown on GaSb substrates and had 5 or 10 active periods sandwiched between broadened-waveguide separate confinement regions and quaternary optical cladding layers. The laser bars were processed into 100-μm wide stripes, cleaved to a cavity length of 1 mm, and mounted junction side down. Lasing was obtained on a number of devices from different laser bars. Both pulsed measurements with 0.5-1 s current pulses applied at a repetition rate of 200 Hz and cw experiments were performed. Spectral characterization indicated a lasing wavelength of 3.18 μm at a temperature of 265 K for the 5-well laser, and 3.28 μm at T= 290 K for the 10-well device