Abstract: A method and apparatus for detecting the presence of a specific concentration of gaseous species within a calibrated range in a gas sample are disclosed. The ILS gas detection system of the present invention simply comprises an ILS laser and an optical detector. However, the spectral bandwidth of the ILS laser is preferably entirely included within one of the absorption bands or regions assigned to the intracavity gaseous species being monitored. Thus, within the calibrated range, the presence of the gaseous species changes the temporal characteristics of the ILS laser. Consequently, only a temporal characteristic of the output of the ILS laser need be monitored in order to quantitatively determine the concentration of the absorbing gaseous species when using the ILS method of the present invention.

Abstract: Contaminants are detected optically at concentrations below 100 part-per-million (ppm) and extending to a level approaching 1 part-per-trillion (ppt) by using intracavity laser spectroscopy (ILS) techniques. An optically-pumped solid-state laser (the ILS laser) is employed as a detector. The ILS laser comprises an ion-doped crystal medium contained in a linear laser cavity. A gas sample containing gaseous contaminant species is placed inside the laser cavity and on one side of the ion-doped crystal. 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. One preferred embodiment of the present invention employs a linear cavity formed between two mirrors separated from the ion-doped crystal laser medium, wherein both ends of the ion-doped crystal are cut at Brewster's angle.

Abstract: A method and apparatus for detecting the presence of a specific concentration of gaseous species within a calibrated range in a gas sample is disclosed. The ILS gas detection system of the present invention simply comprises an ILS laser, a wavelength-selective optical element, and an optical detector. However, the potential or operational wavelength bandwidth of the ILS laser is preferably entirely included within one of the absorption bands or regions assigned to the intracavity gaseous species being monitored. Thus, within the calibrated range, the presence of the gaseous species changes the output laser wavelength or output intensity at a specific wavelength of the ILS laser. Consequently, only the wavelength of the output or the output intensity at the specific wavelength of the ILS laser need be monitored in order to quantitatively determine the concentration of the absorbing gaseous species within a calibrated range when using the ILS method of the present invention.

Abstract: A method and apparatus for detecting the presence of a specific concentration of gaseous species within a calibrated range in a gas sample are disclosed. The ILS gas detection system of the present invention simply comprises an ILS laser and an optical detector. However, the potential or operational wavelength bandwidth of the ILS laser is preferably entirely included within one of the absorption bands or regions assigned to the intracavity gaseous species being monitored. Thus, within the calibrated range, the presence of the gaseous species changes the output laser intensity of the ILS laser. Consequently, only the intensity of the output of the ILS laser need be monitored in order to quantitatively determine the concentration of the absorbing gaseous species when using the ILS method of the present invention.

Abstract: Contaminants are detected optically at concentrations below 100 part-per-million (ppm) and extending to a level approaching 1 part-per-trillion (ppt) by using intracavity laser spectroscopy (ILS) techniques. A diode laser-pumped solid-state laser (the ILS laser) is employed as a detector. The ILS laser comprises an ion-doped crystal medium contained in a laser cavity optically pumped by a diode laser pump laser. A gas sample containing gaseous contaminant species is placed inside the laser cavity and on one side of the ion-doped crystal. 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.

Abstract: On-board ILS ethyl alcohol sensors based on intracavity laser spectroscopy (ILS) are provided for detecting the presence of ethyl alcohol vapors in a vehicle. The sensor comprises: (a) a laser comprising a gain medium having two opposed facets within a laser resonator and functioning as an intracavity spectroscopic device having a first end and a second end, the first end operatively associated with a partially reflecting (i.e., partially transmitting) surface; (b) a reflective or dispersive optical element (e.g.

Abstract: Contaminants are detected optically at concentrations below 1 part-per-million (ppm) and extending to a level approaching 1 part-per-trillion (ppt) by using intracavity laser spectroscopy (ILS) techniques. A solid-state laser with an ion-doped crystal medium contained in an optical resonator cavity (the ILS laser) is employed as a detector. A gas sample containing gaseous contaminant species is placed inside the optical resonator cavity and on one side of the ion-doped crystal. The output signal from the ILS laser is detected and analyzed to identify the gaseous species. The concentration of the gaseous species can be determined as well.

Abstract: 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.

Abstract: Contaminants are detected optically at concentrations below 1 part-per-million (ppm) and extending to a level approaching 1 part-per-trillion (ppt) by using intracavity laser spectroscopy (ILS) techniques. An optically-pumped solid-state laser (the ILS laser) is employed as a detector. The ILS laser comprises an ion-doped crystal medium contained in a linear laser cavity which may be optically pumped by a diode laser pump laser. A gas sample containing gaseous contaminant species is placed inside the laser cavity and on one side of the ion-doped crystal. 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. Advantageously, the linear cavity is relatively small and compact in comparison to other ILS systems.

Abstract: Contaminants are detected optically at concentrations below 1 part-per-million (ppm) and extending to a level approaching 1 part-per-trillion (ppt) by using intracavity laser spectroscopy (ILS) techniques. A solid-state laser with an ion-doped crystal medium contained in an optical resonator cavity (the ILS laser) is employed as a detector. A gas sample containing gaseous contaminant species is placed inside the optical resonator cavity and on one side of the ion-doped crystal. The output signal from the ILS laser is detected and analyzed to identify the gaseous species. The concentration of the gaseous species can be determined as well.