System and method for controlling the light source of a cavity ringdown spectrometer

摘要

A system and method for controlling the light source of a cavity ring-down spectrometer (CRDS). The system comprises a resonant optical cavity having at least two high reflectivity mirrors; a source for providing a continuous wave optical signal into the optical cavity, the source comprising an electrically pumped semiconductor gain medium; and a SOA interposed between the optical signal source and the optical cavity. The SOA receives the optical signal and transmits it to the resonant optical cavity. The system also includes a first detector for monitoring the intensity of radiation emitted from said cavity and generating a first detection signal based thereon; and at least a first controller for deactivating the optical signal based on a comparison of the first detection signal and a predetermined threshold and for thereafter reactivating the optical signal after a delay period in excess of the ring-down time of the optical cavity, the deactivating and reactivating being achieved by respectively turning off and then turning on electrical current to the SOA.