Abstract: A nitric oxide sensor and method is disclosed. The sensor is based on sum-frequency mixing of a tunable, 395-nm external cavity diode laser with a 532-nm diode-pumped intracavity-frequency-doubled Nd:YAG laser in a beta-barium-borate crystal. The output from the BBO crystal is ultraviolet radiation at 227 nm and is split using a 50—50 beam splitter. Half of the radiation is directed into a reference photomultiplier tube, and the other half of the UV radiation is directed through the medium of interest and then directed into a signal photomultiplier tube. The output from the photomultiplier tubes is compared and the difference utilized to indicate the level of nitric oxide by absorption-based spectrosocpic techniques.

Abstract: An all-solid-state continuous-wave (cw) laser system for measurements of the absorption by the CO molecule of mid-infrared radiation in the 4.3-4.6 ?m range is described, wherein a single-mode, tunable output of a 70 mW, 860-nm ECDL is difference frequency mixed with the output of a 550 mW diode-pumped cw Nd:YAG laser in a PPLN crystal to produce approximately 1 ?W of tunable cw radiation at 4.5 ?m.