MEASUREMENTS OF THE POLARIZATION DEPENDENT OF THE GAIN OF STRAINED MULTIPLE QUANTUM-WELL INGAAS-INP LASERS

The polarization dependent gain spectra of both tensile and compressive strain multiple quantum well (MQW) In(x)Ga1-xAs-InP lasers in a relatively large strain regime were measured. MQW lasers having tensile strain with In concentration as low as 43% in the wells were found to lase in a pure transverse magnetic (TM) mode rather than a transverse electric (TE) mode, with a gain difference of 60-70 cm-1 at all the injection current investigated. The peak gain for the TE mode is shifted towards shorter wavelength from that of the TM mode indicating that the emission is principally due to light hole-electron transition. The differential gain of the TM mode was also found to be about 1.5 times higher than the TE mode operation. Opposite effects were observed in the compressive strained MQW lasers.