Characterization of intensity and frequency fluctuations of mid-infrared quantum cascade lasers

Summary form only given. The recent development of quantum cascade (QC) lasers has opened up the availability of tunable laser sources for high-resolution absorption spectroscopy in the mid-infrared (IR). These lasers are fundamentally different than conventional mid-IR diode lasers and are expected to exhibit better noise characteristics. Initial characterizations of QC lasers developed at Bell Laboratories have demonstrated superior stability over lead salt lasers emitting in a similar spectral region. We report the noise characteristics of several single-mode QC lasers operating in a continuous mode at liquid nitrogen temperatures.