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 pola rizations, 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, T he gain-current relationships have been characterized for each polariz ation, and found to cross at a modal gain value of 25 cm(-1). Lasers w hose threshold gain is near this crossover value were found to emit in either one or both polarizations, with a very wide range of polarizat ion asymmetry possible, A simple QW gain model can be used to qualitat ively describe this behavior, along with the tendency toward TE-mode e mission at higher temperature.