SPECTRAL FILTERING FOR TIME ISOLATION OF INTENSIVE PICOSECOND OPTICALPULSES FROM A Q-SWITCHED LASER-DIODE

A significant wavelength separation is found between the shot-pulsed m ode and stationary lasing in the emission band of a Q-switched single- heterostructure laser. This feature allowed a 35 ps/100 W single optic al pulse to be achieved by means of band-pass optical filtering. An at tendant long-duration optical response, attributed to optical transiti ons with at least one localized tail state involved, is suppressed by a factor of 10(4) as compared with the peak power of the single picose cond pulse. A complicated time-resolved spectrum is interpreted in ter ms of a qualitative model involving saturable absorption and carrier h eating. (C) 1998 American Institute of Physics. [S0021-8979(98)06716-4 ]