Long-wavelength semiconductor lasers for high resolution spectroscopy

The authors report an InPAsSb laser for the spectral range of 2.8-3.6 μm for application to diode laser spectroscopy (DLS). For high resolution spectroscopy it is necessary to have single mode or quasi single mode lasers with continuous tuning of the emission wavelength by current or/and by temperature. The important parameter for DLS is the shift of a longitudinal mode position with current and temperature, which is discussed. Good mode structure of the laser emission, relatively high optical power and a possibility of continuous wave operation above liquid nitrogen temperature are the attractive factors for spectroscopy. First experiments showed that the lasers can be successfully used for DLS