Mid-infrared-scanning cavity ring-down CH(2)F(2) detection using electronically tuned Cr:ZnSe laser

The development of mid-infrared (mid-IR) tunable lasers has been driving various laser spectroscopic technologies. Herein, we report wavelength-scanning cavity ring-down spectroscopy (WS-CRDS) in the mid-IR region using an electronically tuned Cr:ZnSe (ET-Cr:ZnSe) laser, which could achieve a nanosecond pulse operation, with broad wavelength tuning of 2–3 µm. This allowed WS-CRDS-induced trace detection of the refrigerant, CH(2)F(2). A CH(2)F(2) detection limit of 0.66 ppm (3σ), and the detection of trace H(2)O in CH(2)F(2) was realized using the broad wavelength-tuning range feature, demonstrating the effectiveness of the ET-Cr:ZnSe laser in WS-CRDS. We believe that our method would accelerate the development of various trace-gas detection technologies.