Strongly Asymmetric Waveguide Semiconductor Lasers for Picosecond Pulse Generation by Gain- and Q-Switching

We present theoretical investigation of single-and double-section high power semiconductor lasers with strongly asymmetric waveguides with a very large active layer thickness to optical confinement factor ratio, for generation of picosecond pulses. It is shown that such laser constructions compare favourably with alternative constructions as regards generating high-energy, trail-free pulses in a single transverse mode, with high electric to optical power conversion efficiency. Laser performance and operating characteristics under gain and combined gain/Q-switching operating regimes are analysed and compared. For the case of the combined regime in a double-section laser, experimental observation of high-energy trail-free pulses is reported.