DIODE LASER-PUMPED AND LINEAR CAVITY LASER SYSTEMS FOR ULTRA-SENSITIVE GAS DETECTION VIA INTRACAVITY LASER SPECTROSCOPY (ILS)

摘要

Contaminants are detected at concentrations below 1 part-per-million and extending to a level approaching 1 part-per-trillion by using intracavity laser spectroscopy (ILS) techniques. An optically-pumped solid-state (ILS laser) (500) is employed as a detector. The ILS laser (500) comprises an iondoped crystal (507) in a laser cavity (902) optically pumped by a pumping source (100). A gas sample containing gaseous contaminant species is placed inside the laser cavity (902) on one side of crystal (507). The ILS laser output signal is detected and analyzed to identify the gaseous species (via its spectral signature). Gaseous species concentration can also be determined from the spectral signature. In one embodiment, the ILS laser (500) comprises an ion-doped crystal medium (507) which is pumped by a semiconductor diode laser. In another embodiment, the ILS laser (500) comprises an ion-doped crystal medium (507) in a linear cavity (902).