Current-tunable lasers with a narrow emission line operating at 3.3 mu m

Current-tunable diode lasers with narrow emission lines for laser spectrosc opy in the 3.2-3.4 mum wavelength range are developed. The lasers, based on an InAsSb/InAsSbP double heterostructure, have a wide-stripe cavity. The w ave number increases from 3030 to 3034 cm(-1) as the current is raised from 1.5 to 3 times the threshold value at 70 K, while the full width at half-m aximum of the laser line decreases from 18 to 10 MHz. It is demonstrated th at the linewidth is determined by fluctuations of the cavity resonance freq uencies as a result of fluctuations in the concentration of nonequilibrium charge carriers. (C) 2001 MAIK "Nauka/Interperiodica".