초록 ▼

Contaminants in corrosive gases are detected optically at concentrations below 1 part-per-million (ppm) and extending to a level below 1 part-per-billion (ppb) by using intracavity laser spectroscopy (ILS) techniques. A laser, the ILS laser, is employed as a detector. The ILS laser comprises a gain

Contaminants in corrosive gases are detected optically at concentrations below 1 part-per-million (ppm) and extending to a level below 1 part-per-billion (ppb) by using intracavity laser spectroscopy (ILS) techniques. A laser, the ILS laser, is employed as a detector. The ILS laser comprises a gain medium contained in a laser cavity. A gas sample containing gaseous contaminant species is contained within a gas sample cell which is placed inside the laser cavity and on one side of the gain medium. Accordingly, the corrosive gas is prevented from reacting with the components of the ILS laser. The output signal from the ILS laser is detected and analyzed to identify the gaseous species (via its spectral signature). The concentration of the gaseous species can be determined from the spectral signature as well.

대표청구항 ▼

[ What is claimed is:] [1.] A method for detecting the presence of gaseous species in a gas sample containing corrosive gas, comprising the steps of:(a) selecting a spectral region wherein (i) said gaseous species has at least one absorption feature and (ii) said corrosive gas has essentially no int

[ What is claimed is:] [1.] A method for detecting the presence of gaseous species in a gas sample containing corrosive gas, comprising the steps of:(a) selecting a spectral region wherein (i) said gaseous species has at least one absorption feature and (ii) said corrosive gas has essentially no interfering absorption features;(b) providing a laser comprising a laser cavity and a gain medium which resides therein, said gain medium outputting light having a wavelength distribution at least a portion of which is in said selected spectral region;(c) providing a gas sample cell having windows which are transparent to light in said selected spectral region such that a beam of light can pass through said gas sample cell;(d) inserting said gas sample cell in said laser such that light output from said gain medium passes through said gas sample cell prior to exiting said laser cavity;(e) inserting said gas sample containing said corrosive gas in said gas sample cell such that light output from said gain medium passes through said gas sample, said gas sample sealed within said gas sample cell such that said corrosive gas does not react with said laser; and(f) directing said light output from said gain medium after exiting said laser cavity to a detector assembly for determining the presence and/or concentration of said gaseous species in said gas sample.