The nature of lasing threshold in passively Q-switched GaAs/AlGaAs lasers with saturable absorbers formed by heavy ion implantation is investigated in this article. After studying various laser characteristics, including threshold current density, differential quantum efficiency, spectral output, and picosecond time-resolved emission, we conclude that the origin of the Q-switching is unlikely to be caused by spontaneous emission or mode locking, and that collective coherent radiation effects may contribute to the onset of lasing. © 1998 American Institute of Physics.
|Number of pages||4|
|Journal||Journal of Applied Physics|
|Publication status||Published - 15 Nov 1998|