Monomode Interband Cascade Lasers at 5.2 $\mu{\rm m}$ for Nitric Oxide Sensing

We demonstrate application-grade monomode distributed feedback (DFB) laser devices with emission wavelength around 5.2 μm; suitable for nitric oxide sensing. The devices are based on interband cascade laser material that enables continuous wave operation in the midinfrared spectral region when mounted on a standard thermoelectrically cooled TO-style header. With etched vertical sidewall DFB gratings as wavelength selective elements, signal to noise ratios around 30 dB and typical tuning ranges greater than 12 nm were achieved, making the devices suitable for applications based on tunable laser absorption spectroscopy.