Innovative Lasers Corp.

Innovative Lasers Coropration

George H Atkinson

Jeffrey S Pilgrim

Esmail Mehdizadeh

Markus A Wolperdinger

Max F Hineman

Yu Yan

Jiamin Zhang

Yehoshua Kalisky

A gas cell is provided for detection of trace gases via intracavity laser spectroscopy. The gas cell comprises a gas cell body having a long body axis, an interior hollow portion along the long body axis, and two end portions, each end portion having two opposed surfaces, one surface of each the end portion cut to an angle with respect to the long body axis and including a laser-transparent window on each face defining ends of the interior hollow portion. The angle is dependent on operating wavelength of the spectrometer and refractive index of the window material at the operating wavelength. Each end portion is provided with a gas line connection in the proximity of the opposed surface, one gas line for introducing a sample gas into the interior hollow portion and the other gas line for exhausting the sample gas from the interior portion. Further, a gas cell holder is provided for supporting and positioning the gas cell. The gas cell holder comprises: (a) front, back, top, and bottom surfaces for encompassing the gas cell; and (b) multiple means for providing multiple degrees-of-freedom movement of the gas cell. The combination of the gas cell and the gas cell holder provides a compact laser resonator cavity. The gas cell holder provides the gas cell with multiple degrees of freedom of adjustment and maintains the position of the gas cell after alignment.

Gas cell for detection of trace gases via intracavity laser spectroscopy

In accordance with the present invention, a high-resolution, compact spectrometer is provided for dispersing wavelengths .lambda. of an incoming beam for detection by a detector. The spectrometer comprises: (a) an entrance slit through which the incoming beam passes; (b) a first mirror for collimating the beam from the entrance slit; (c) a first reflectance grating for dispersing the collimated beam to form a beam having a spectral intensity distribution, the first reflectance grating having a number of grooves N.sub.1 ; (d) a second reflectance grating for further dispersing the collimated beam, the second reflectance grating having a number of grooves N.sub.2 ; and (e) a second mirror for focusing the collimated and dispersed beam, wherein the spectrometer has a substantially symmetrical construction. The symmetrical construction of the spectrometer doubles the resolution and dispersion of the gratings. The compact and high-resolution imaging spectrometer is capable of measuring the absorption lines of gases in high sensitivity gas sensors with an intracavity cell.

High-resolution, compact intracavity laser spectrometer

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.

Contaminant identification and concentration determination by monitoring

On-board ILS sensors for detecting illegal drugs and based on intracavity laser spectroscopy (ILS) are provided for detecting the presence of drugs and their metabolized by-product vapors in an enclosed space, such as 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., a mirror or a diffraction grating) operatively associated with the second end to define a broadband wavelength laser resonator between the optical element and the first end and to thereby define an external cavity region between at least one facet of the gain medium and either the first end or the second end or both ends; (c) the external cavity region being exposed to air in the enclosed space to enable any drugs or their metabolized by-product molecules to enter thereinto; (d) a detector spaced from the first end; (e) appropriate electronics for measuring and analyzing the detector signal; (f) a housing for containing at least the laser, the partially reflecting surface, and the optical element, the housing being configured to prevent escape of stray radiation into the enclosed space and to permit air from the enclosed space to continuously circulate through the external cavity region for analysis; and (g) means for driving the laser (e.g., electrical or optical). A method is provided for measuring concentration of drug vapors and their metabolized by-product vapors in the vehicle or other enclosed space employing the on-board sensor. The method comprises: (1) sensing any drugs and their metabolized by-product vapors in the enclosed space by the on-board sensor; and (2) providing a signal indicative of presence of any drugs or metabolized vapors.

ILS sensors for drug detection within vehicles

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.

Linear cavity laser system for intracavity laser spectroscopy

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.

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.

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.

Diode laser-pumped laser system for intracavity laser spectroscopy (ILS)

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., a mirror or a diffraction grating) operatively associated with the second end to define a broadband wavelength laser resonator between the optical element and the first end and to thereby define an external cavity region between at least one facet of the gain medium and either the first end or the second end or both ends; (c) the external cavity region being exposed to air in the cabin of the vehicle to enable any ethyl alcohol molecules to enter thereinto; (d) a detector spaced from the first end; (e) appropriate electronics for measuring and analyzing the detector signal; (f) a housing for containing at least the laser, the partially reflecting surface, and the optical element, the housing being configured to prevent escape of stray radiation into the cab and to permit air from the cab to continuously circulate through the external cavity region for analysis; and (g) means for driving the laser (e.g., electrical or optical). A method is provided for measuring concentration of ethyl alcohol vapors in a vehicle employing the on-board sensor. The method comprises: (1) sensing any ethyl alcohol vapors in the cab by the on-board sensor; and (2) providing a signal indicative of presence of any alcohol vapors.

ILS sensors for alcohol detection within vehicles

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.

Intracavity laser spectroscopy for high sensitivity detection of

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 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. Advantageously, the diode laser pump laser is relatively small and compact in comparison to other sources of optical pumping. Additionally, the small/compact size of the diode laser pump laser makes the gas detection system constructed therewith amenable to a broad variety of practical applications.

Diode laser-pumped laser system for ultra-sensitive gas detection via

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.

Ultra-sensitive detection of contaminants in corrosive gas via

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. Additionally, the small/compact size of the linear cavity makes the gas detection system constructed therewith amenable to a broad variety of practical applications.

Growing community of inventors

Tucson, AZ, United States of America

George H Atkinson