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Phase modulated spectrophotometery
NewPatents
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between the limits are selectively variable. Output readings from the spectrophotometer are taken at equal angular increments of the grating and these readings are converted to values occurring at equal wavelength increments by a computer.
4978852 HADAMARD TRANSFORM MEASUREMENT OF MSN FOURIER-TRANSFORM MASS SPECTRA Evan R Williams, Fred W McLafferty assigned to Cornell Research Foundation Inc
4970396 INFRAREDSPECTRA RECORDING, HIGH PRESSURE SAMPLE HOLDER Patrick T T Wong, Ottawa, Canada assigned to National Research Council of Canada/Conseil National de Recherches du Canada An infrared absorption spectra recording, high pressure sample holder comprises a gasket for high compression between two diamond anvils, and an infrared light beam transmitting material partially filling a light passage through the gasket at a position between the two anvils to leave an infrared light beam transmitting, sample cavity adjacent one anvil. The surface of the filling is shaped, e.g. dished so that an infrared light beam passing through the sample will have light paths of different lengths, thereby avoiding optical interference fringes.
4972331 PHASE MODULATED SPECTROPHOTOMETRY Britton Chance assigned to Nim Inc The present invention to provides methods and apparatus for studying photon migration using signal modulation techniques such as time, frequency and phase modulation. The photon migration data may then be converted, using the principles of time-resolved spectroscopy, to determine the concentration of an absorptive constituent in a scattering medium, such as the concentration of hemoglobin in a brain of other tissue. The methods and apparatus of the present invention provide as a specific embodiment, a dual wavelength phase modulation system which allows the clinical application of time resolved spectroscopy in a commerically feasible embodiment.
The simultaneous collection of multiple spectra using tandem and multidimensional mass spectrometry from multiple precursors yields correspondingly enhanced sensitivity through Hadamard transform deconvolution. For MSn spectra, the product relationships are coded by a Hadamard differences method wherein the combined daughter spectrum of a selected half of the precursors is subtracted from the combined daughter spectrum of the remaining precursors, so that no ions are lost.
4980566 ULTRASHORT PULSE MULTICHANNEL INFRARED SPECTROMETER APPARATUS AND METHOD FOR OBTAINING ULTRAFAST TIME RESOLUTION SPECTRAL DATA Edwin J Heilweil assigned to The United States of America as represented by the Secretary of Commerce A simple, compact optical spectrometer employs solid-state nonlinear crystals for obtaining broadband multichannel infrared spectra with picosecond or femtosecond time resolution. Spectrally broad infrared pulses are produced by difference frequency mixing in a first LiI03 crystal between the second harmonic of a picosecond Nd + 3:YAG laser and broadband output of a synchronously pumped dye laser, and a resultant broadband IR pulse is upconverted by a second LiI03 crystal to yield a blue visible pulse which is dispersed by a 0.25 meter spectrograph onto amultichannel vidicon or reticon detector to obtain four wavenumber resolution single-shot transient infrared spectra of a sample. The present invention enables rapid acquisition of ultrashort time infrared spectra over a broadly tunable spectral range (in the mid to near infrared) at minimal cost and by a simple but versatile optical system employing readily available components.
ii
between the limits are selectively variable. Output readings from the spectrophotometer are taken at equal angular increments of the grating and these readings are converted to values occurring at equal wavelength increments by a computer.
4978852 HADAMARD TRANSFORM MEASUREMENT OF MSN FOURIER-TRANSFORM MASS SPECTRA Evan R Williams, Fred W McLafferty assigned to Cornell Research Foundation Inc
4970396 INFRAREDSPECTRA RECORDING, HIGH PRESSURE SAMPLE HOLDER Patrick T T Wong, Ottawa, Canada assigned to National Research Council of Canada/Conseil National de Recherches du Canada An infrared absorption spectra recording, high pressure sample holder comprises a gasket for high compression between two diamond anvils, and an infrared light beam transmitting material partially filling a light passage through the gasket at a position between the two anvils to leave an infrared light beam transmitting, sample cavity adjacent one anvil. The surface of the filling is shaped, e.g. dished so that an infrared light beam passing through the sample will have light paths of different lengths, thereby avoiding optical interference fringes.
4972331 PHASE MODULATED SPECTROPHOTOMETRY Britton Chance assigned to Nim Inc The present invention to provides methods and apparatus for studying photon migration using signal modulation techniques such as time, frequency and phase modulation. The photon migration data may then be converted, using the principles of time-resolved spectroscopy, to determine the concentration of an absorptive constituent in a scattering medium, such as the concentration of hemoglobin in a brain of other tissue. The methods and apparatus of the present invention provide as a specific embodiment, a dual wavelength phase modulation system which allows the clinical application of time resolved spectroscopy in a commerically feasible embodiment.
The simultaneous collection of multiple spectra using tandem and multidimensional mass spectrometry from multiple precursors yields correspondingly enhanced sensitivity through Hadamard transform deconvolution. For MSn spectra, the product relationships are coded by a Hadamard differences method wherein the combined daughter spectrum of a selected half of the precursors is subtracted from the combined daughter spectrum of the remaining precursors, so that no ions are lost.
4980566 ULTRASHORT PULSE MULTICHANNEL INFRARED SPECTROMETER APPARATUS AND METHOD FOR OBTAINING ULTRAFAST TIME RESOLUTION SPECTRAL DATA Edwin J Heilweil assigned to The United States of America as represented by the Secretary of Commerce A simple, compact optical spectrometer employs solid-state nonlinear crystals for obtaining broadband multichannel infrared spectra with picosecond or femtosecond time resolution. Spectrally broad infrared pulses are produced by difference frequency mixing in a first LiI03 crystal between the second harmonic of a picosecond Nd + 3:YAG laser and broadband output of a synchronously pumped dye laser, and a resultant broadband IR pulse is upconverted by a second LiI03 crystal to yield a blue visible pulse which is dispersed by a 0.25 meter spectrograph onto amultichannel vidicon or reticon detector to obtain four wavenumber resolution single-shot transient infrared spectra of a sample. The present invention enables rapid acquisition of ultrashort time infrared spectra over a broadly tunable spectral range (in the mid to near infrared) at minimal cost and by a simple but versatile optical system employing readily available components.