Dual wavelength operation of the GaSb-based Y-branch distributed Bragg reflector lasers near 2.1 μm

The GaSb-based diode lasers operating simultaneously at two wavelengths near 2.1 μm have been designed and fabricated. The Y-branch devices used the 6th order distributed Bragg reflectors (DBR) to provide spectrally selective feedback. The laser active region contained two asymmetric quantum wells with allowed optical transitions between two lowest electron (e1 and e2) and top hole (hh1) subbands. The laser emission lines loosely matched the e1-hh1 and e2-hh1 optical transitions with separation corresponding to ∼3.1 THz. The 10 μm wide deeply etched straight ridge DBR lasers demonstrated stable single mode operation with more than 50 mW of output power.