Abstract: A high-speed absorption spectrographic system employs a slit-less spectroscope to obtain high-resolution, high-speed spectrographic data of combustion gases in an internal combustion engine allowing precise measurement of gas parameters including temperature and species concentration.

Abstract: A high-speed absorption spectrographic system employs a slit-less spectroscope to obtain high-resolution, high-speed spectrographic data of combustion gases in an internal combustion engine allowing precise measurement of gas parameters including temperature and species concentration.

Abstract: A high-speed absorption spectrographic system employs a slit-less spectroscope to obtain high-resolution, high-speed spectrographic data of combustion gases in an internal combustion engine allowing precise measurement of gas parameters including temperature and species concentration.

Abstract: An apparatus and method are provided for conducting heterodyne frequency-comb spectroscopy. The apparatus includes a first and second frequency-comb generators for generating corresponding first and second continuous wave laser beams, respectively. The first beam defines a spectrum of light having a plurality of modes spaced by a first frequency. The second beam defines a spectrum of light having a plurality of modes spaced by a second frequency that is greater than the first frequency. The first and second beams are combined and the optical power of the combined beam is monitored with a data acquisition system to record a time trace. The recorded time trace is Fourier transformed such that each of spectrums of the first and second beams will exhibit a low-frequency comb. By superimposing the two combs, a beat frequency in a low-frequency region is assigned to an optical frequency.

Abstract: A high-speed absorption spectrographic system employs a slit-less spectroscope to obtain high-resolution, high-speed spectrographic data of combustion gases in an internal combustion engine allowing precise measurement of gas parameters including temperature and species concentration.

Abstract: An external cavity laser may be swept rapidly in frequency and cavity length to prevent formation of modes providing improved spectral response and light characteristics.

Abstract: An apparatus and method are provided for conducting heterodyne frequency-comb spectroscopy. The apparatus includes a first and second frequency-comb generators for generating corresponding first and second continuous wave laser beams, respectively. The first beam defines a spectrum of light having a plurality of modes spaced by a first frequency. The second beam defines a spectrum of light having a plurality of modes spaced by a second frequency that is greater than the first frequency. The first and second beams are combined and the optical power of the combined beam is monitored with a data acquisition system to record a time trace. The recorded time trace is Fourier transformed such that each of spectrums of the first and second beams will exhibit a low-frequency comb. By superimposing the two combs, a beat frequency in a low-frequency region is assigned to an optical frequency.

Abstract: A high scan rate spectroscopic system converts a narrow-band laser pulse into a multispectral pulse, using, for example, a nonlinear fiber. The multispectral pulse is then converted to a swept frequency pulse through a second fiber impressing a frequency-dependent delay in the light beam which is then applied to the object to be tested.

Abstract: A high scan rate spectroscopic system converts a narrow-band laser pulse into a multispectral pulse, using, for example, a nonlinear fiber. The multispectral pulse is then converted to a swept frequency pulse through a second fiber impressing a frequency-dependent delay in the light beam which is then applied to the object to be tested.

Abstract: The present invention provides a laser-based method and apparatus that uses absorption spectroscopy to detect the mole fraction of CO2 in a high temperature gas stream. In a preferred embodiment, a distributed feedback based diode laser sensor operating at a wavelength near 1996.89 nm (5007.787 cm−1) interrogates the R(50) transition of the &ngr;1+2&ngr;2+&ngr;3 CO2 absorption band in the near infrared. This transition is specifically chosen based on its superior linestrength and substantial isolation from interfering absorption by high-temperature H2O, CO, NH3, N2O, NO, and other species commonly present in combustion or other high-temperature gas flows.

Abstract: An emergency vehicle alert system includes an emergency vehicle unit, a motor vehicle unit and a plurality of global positioning system (GPS) signals. The emergency vehicle unit includes an emergency GPS receiver, and RF transmitter. The motor vehicle unit includes a vehicle GPS receiver, RF receiver, microcontroller, and warning display. The emergency GPS receiver inputs at least three GPS signals from a plurality of GPS satellites. The emergency GPS receiver transforms the at least three GPS signals into an emergency location signal string. The emergency location signal string is transmitted by the RF transmitter. Each RF receiver which is within range of the emergency vehicle transmission will receive the emergency location signal string. The vehicle GPS receiver inputs at least three different GPS signals from the plurality of GPS satellites. The vehicle GPS receiver transforms the at least three different GPS signals into a vehicle location signal string.

Abstract: A device for measuring the levitation force of a high temperature superconductor sample with respect to a reference magnet includes a receptacle for holding several high temperature superconductor samples each cooled to superconducting temperature. A rotatable carousel successively locates a selected one of the high temperature superconductor samples in registry with the reference magnet. Mechanism varies the distance between one of the high temperature superconductor samples and the reference magnet, and a sensor measures levitation force of the sample as a function of the distance between the reference magnet and the sample. A method is also disclosed.