Miniature tunable laser spectrometer for detection of a trace gas
First Claim
1. An open-path laser spectrometer for measuring a concentration of a trace gas, the open-path laser spectrometer comprising:
- an open-path multi-pass analysis region comprising a first mirror, a second mirror at a distance and orientation from the first mirror, and a support structure for locating the first and second mirrors;
a laser coupled to the open-path multi-pass analysis region and configured to emit light of a wavelength range and to enable a plurality of reflections of the emitted light between the first and second mirrors;
a detector coupled to the open-path multi-pass analysis region and configured to detect a portion of the emitted light interacting with the trace gas and impinging on the detector and to generate a return signal corresponding to a characteristic of the detected portion of the emitted light; and
an electronic system coupled to the laser and the detector,wherein the electronic system;
monitors a spectrum of the generated return signal to determine a shift in a resonance line-center of the trace gas with respect to an injected laser current, as compared to an initial resonance line-center of the trace gas with respect to the injected laser current;
adjusts a temperature of the laser, based on the determined shift, to return the resonance line-center of the trace gas with respect to the injected laser current back to the initial resonance line-center of the trace gas with respect to the injected laser current; and
measures the concentration of the trace gas based on the generated return signal.
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Accused Products
Abstract
An open-path laser spectrometer (OPLS) for measuring a concentration of a trace gas, the OPLS including an open-path multi-pass analysis region including a first mirror, a second mirror at a distance and orientation from the first mirror, and a support structure for locating the mirrors, a laser coupled to the analysis region and configured to emit light of a wavelength range and to enable a plurality of reflections of the emitted light between the mirrors, a detector coupled to the analysis region and configured to detect a portion of the emitted light impinging on the detector and to generate a corresponding signal, and an electronic system coupled to the laser and the detector, and configured to adjust the wavelength range of the emitted light from the laser based on the generated signal, and to measure the concentration of the trace gas based on the generated signal.
36 Citations
20 Claims
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1. An open-path laser spectrometer for measuring a concentration of a trace gas, the open-path laser spectrometer comprising:
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an open-path multi-pass analysis region comprising a first mirror, a second mirror at a distance and orientation from the first mirror, and a support structure for locating the first and second mirrors; a laser coupled to the open-path multi-pass analysis region and configured to emit light of a wavelength range and to enable a plurality of reflections of the emitted light between the first and second mirrors; a detector coupled to the open-path multi-pass analysis region and configured to detect a portion of the emitted light interacting with the trace gas and impinging on the detector and to generate a return signal corresponding to a characteristic of the detected portion of the emitted light; and an electronic system coupled to the laser and the detector, wherein the electronic system; monitors a spectrum of the generated return signal to determine a shift in a resonance line-center of the trace gas with respect to an injected laser current, as compared to an initial resonance line-center of the trace gas with respect to the injected laser current; adjusts a temperature of the laser, based on the determined shift, to return the resonance line-center of the trace gas with respect to the injected laser current back to the initial resonance line-center of the trace gas with respect to the injected laser current; and measures the concentration of the trace gas based on the generated return signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method for measuring a concentration of a trace gas comprising:
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providing an open-path laser spectrometer comprising; an analysis region comprising a first mirror and a second mirror at a distance from the first mirror; a laser; a detector; and an electronic system, wherein the laser is configured to emit light of a wavelength range toward the second mirror, the emitted light reflecting off of the first and second mirrors a plurality of times before impinging on the detector; exposing the analysis region of the open-path laser spectrometer to the ambient atmosphere; detecting, by the detector, a characteristic of a portion of the emitted light interacting with the trace gas and impinging on the detector, and generating, by the detector, a return signal corresponding to the detected characteristic of the impinging light; monitoring, by the electronic system, a spectrum of the generated return signal to determine a shift in a resonance line-center of the trace gas with respect to an injected laser current, as compared to an initial resonance line-center of the trace gas with respect to the injected laser current; adjusting, by the electronic system, a temperature of the laser, based on the determined shift, to return the resonance line-center of the trace gas with respect to the injected laser current back to the initial resonance line-center of the trace gas with respect to the injected laser current; and measuring, by the electronic system, a concentration of the trace gas based on the generated return signal. - View Dependent Claims (18, 19, 20)
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Specification