DUAL-POLARIZATION, SINGLE-QUANTUM-WELL ALGAINP LASER-DIODE STRUCTURE

A single quantum-well Ga0.5+deltaIn0.5-deltaP/(AlGa)(0.5)In0.5P laser structure is demonstrated, which can provide similar gain in both polarizations, The slightly tensile-strained quantum-well has a light-hole ground state, which gives the lowest transparency current for TM-mode gain, However, the TE-mode gain is dominant at high drive currents, The gain-current relationships have been characterized for each polarization, and found to cross at a modal gain value of 25 cm(-1). Lasers whose threshold gain is near this crossover value were found to emit in either one or both polarizations, with a very wide range of polarization asymmetry possible, A simple QW gain model can be used to qualitatively describe this behavior, along with the tendency toward TE-mode emission at higher temperature.