Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An optical resonator by which reflectivity of ring-down cavity mirrors can be altered and enhanced by adding external optical cavities that recycle light to the main cavity. A coupled-cavity ring-down spectroscopy (CC-RDS) is used for controlling the finesse of an optical resonator. Applications include extending the sensitivity and dynamic range of a cavity-enhanced spectrometer as well as widening the useful spectral region of high-reflectivity mirrors. CC-RDS uses controlled feedback of the probe laser beam to a ring-down cavity, which leads to interference between the internally circulating light and that which is fed back through a cavity mirror port.

Abstract: 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/??FWHM) 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?1). 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).

Abstract: A photoacoustic spectrometer that is intensity-modulated, laser-driven and with a calculable cell constant. The axially symmetrical photoacoustic spectrometer combines first-principles models of acoustic wave propagation with high-resolution spectroscopic measurements, and takes into account molecular relaxation. The spectrometer includes a duct and two chambers disposed at the end of the duct. Inlet and exit tubes, which are disposed in substantially the location of acoustic pressure nodes, permit the gas, gaseous mixture or aerosol to enter and exit the spectrometer. The absolute response of the spectrometer may be modeled and measured. A detailed theoretical analysis of the system and its predicted response may be predicted as a function of gas properties, resonance frequency and sample energy transfer relaxation rates.

Abstract: Signal lamp assembly comprising a light source surrounded by transparent lens walls in four horizontal directions is produced by molding the lens walls in two portions and securing them together. Lens patterns can be molded in three directions, but due to molding limitations, the fourth side cannot be easily molded into a lens configuration. In order to provide a lens for the fourth side, a separately made molded lens insert is placed in receiving and retaining grooves prior to the housing portions being secured together. The resultant assembly retains the insert in desired position and lens walls are thereby effectively provided in the four directions.

Abstract: A molded synthetic resin signal lamp is formed by a pair of facing molded bowl shaped housing portions welded or otherwise connected together along a seam. In order to cover the seam to provide a more attractive appearance, the contact line is located beneath a groove and covered by an opaque band or strip. The band has mounting projections to facilitate assembly with one of the housing portions and the other housing portion is assembled therewith in a manner to sandwich the strip in the groove.

Abstract: This invention provides a novel device for shock mounting a lamp within housing means for a lamp that is particularly intended for use with motorized vehicles, such as farm tractors and other vehicles designed for cross-country travel, as well as over-the-road trucks and the like. Basically, the novel device of the present invention comprises a hollow generally frustoconical resilient member having a long-central axis extending between centers of its opposite ends, with one of the opposite ends of that member including means for retaining, supporting and locating a lamp in a predetermined position, and the other of the opposite ends of that member including means for fastening that member to the lamp housing means, and that member including plural segments positioned around the long-central axis and extending between the opposite ends of that member, with each of the plural segments being generally serpentine in its longitudinal extension with respect to that axis.