Mid-infrared quantum cascade lasers combs for spectroscopy

The quantum cascade laser (QCL)[1] has demonstrated operation over an extremely wide wavelength range extending from the mid-infrared at 2.9μm to the Terahertz at 360μm. In addition, quantum cascade lasers operating in the mid-infrared have now demonstrated extremely high powers (>1W c.w.) with increasingly high wallplug efficiencies (>25%)[2, 3]. As shown in Fig. 1, in a new development, ultra low dissipation devices have been fabricated, operating with powers below 1W at room temperature.