EXPERIMENTAL INVESTIGATION OF THE DIFFERENTIAL GAIN IN SEMICONDUCTOR-LASERS AND ITS INFLUENCE ON Q-SWITCHING PERFORMANCE

The gain spectra of AlCaInP, single quantum well, laser diodes were ob tained by measurement of their spontaneous emission spectra and subseq uent conversion according to the Einstein relations. From these spectr a the ratio of differential absorption to differential gain, gamma was calculated. At energies greater than the lasing transition a threefol d increase in the differential absorption may be achieved in compressi vely strained devices, giving a value of gamma=14.4. These results ind icate that by detuning the saturable absorber energy within a Q-switch ed device by 20 meV a doubling of the inversion factor may be obtained . (C) 1996 American Institute of Physics.