Government of the United States of America, As Represented by the Secretary of Commerce

Other

Joseph Terence Hodges

David A Long

Adam Joseph Fleisher

Kevin O Douglass

David F Plusquellic

Keith Alan Gillis

Gar-Wing Truong

Jeremie Courtois

Stephen E Maxwell

A cavity buildup dispersion spectrometer includes a shutter that modulates coherent electromagnetic radiation at a shutter frequency; and produces modulated electromagnetic radiation; a frequency shifter that frequency shifts the modulated electromagnetic radiation to a shifter frequency and produces frequency shifted radiation; a resonator that produces cavity radiation from the frequency shifted radiation and the coherent electromagnetic radiation, receives an analyte; subjects the analyte to cavity radiation, and transmits the cavity radiation as transmitted electromagnetic radiation; and a receiver that: produces a detector signal from the transmitted electromagnetic radiation, such that the detector signal includes a beat frequency that corresponds to a change in a motion of resonator that includes a change in the distance between the mirrors or a change of refractive index of the analyte in the intracavity space.

Cavity buildup dispersion spectrometer and performing cavity buildup dispersion spectroscopy

A linear absorption spectrometer includes: a laser light source that provides mid-infrared laser light; a high finesse optical resonator that includes: a sample cell operating at a temperature from 220 K to 300 K during linear absorption of mid-infrared laser light by radiocarbon and including: a linear absorption optical path length greater than a kilometer; a first zero-pressure difference mirror mount on which a first supermirror is disposed; a second zero-pressure difference mirror mount on which a second supermirror is disposed; an optical switch interposed between the laser light source and the high finesse optical resonator that modulates and communicates mid-infrared laser light to the high finesse optical resonator; a photoreceiver that receives cavity ring down light and includes a noise equivalent power that is less than a shot noise limit of cavity ring down light.

Linear absorption spectrometer to optically determine an absolute mole fraction of radiocarbon in a sample

A comb source includes a continuous wave frequency source to provide a continuous wave radiation; a first modulator in optical communication with the continuous wave frequency source; a second modulator in optical communication with continuous wave frequency source; and a waveform driver in electrical communication with the first modulator and the second modulator. A process for producing an analyte spectrum includes producing a first comb from a continuous wave frequency and a first waveform; producing a reference comb and a probe comb from the first comb; subjecting a sample to the probe comb; producing a sample comb in response to subjecting the sample to the probe comb; producing a composite comb from the reference comb and the sample comb; producing a second comb from the continuous wave frequency and a second waveform; and combining the second comb and the composite comb to produce the analyte spectrum.

Variable-frequency optical combs, heterodyne sensor, and process for performing spectroscopy

A coupled-cavity ring-down spectrometer utilizes an optical resonator to increase the reflectivity of ring-down cavity mirrors by adding external optical cavities that recycle light to the main cavity. These input and output cavities are made up of at least one coupling mirror and at least one movable recycling mirror. The movable recycling mirrors are coupled to at least one piezoelectric transducer, which generates movement of the recycling mirrors. The coupled-cavity ring-down configuration achieves higher spectrometer finesse, sensitivity and dynamic range.

Coupled cavity spectrometer with enhanced sensitivity and dynamic range

A fast switching arbitrary frequency light source for broadband spectroscopic applications. The light source may operate near 1.6 um based on sideband tuning using an electro-optic modulator driven by an arbitrary waveform generator. A Fabry-Perot filter cavity selects a single sideband of the light source. The finesse (FSR/&#x394;&#x3bd;) of the filter cavity may be chosen to enable rapid frequency switching at rates up to 5 MHz over a frequency range of 40 GHz (1.3 cm). The bandwidth, speed and spectral purity are high enough for spectroscopic applications where rapid and discrete frequency scans are needed. Significant signal-to-noise advantages may be realized using the rapid and broadband scanning features of this system in many areas of spectroscopy, e.g., process monitoring and control, reaction dynamics, and remote sensing (e.g., greenhouse gas monitoring, biological/chemical agent screening).

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Washington Grove, MD, United States of America

Joseph Terence Hodges