Optically pumped semiconductor platelet lasers

Tunable CW laser action of platelet semiconductors is reported in both mode-locked and unmode-locked configurations. The gain media are platelets of CdS, CdSe, CdSSe, and InGaAsP cooled to 85 K and longitudinally pumped by an argon-ion laser. Antireflection (AR) coating of the crystal face and external bandwidth restriction have been used to generate pulses as short as 4 ps. The pulses observed are chirped, with nontransform limited time-bandwidth products of about 1.7. The energy conversion efficiency is 20 percent into the TEM00mode, with output powers of over 10 mW from CdS.