Optical: systems and elements – Optical modulator – Light wave temporal modulation
Patent
1998-02-05
1999-12-28
Ben, Loha
Optical: systems and elements
Optical modulator
Light wave temporal modulation
359247, 359281, 359252, 356437, 2503385, G02F 103
Patent
active
060089288
ABSTRACT:
A multi-gas sensor is provided which modulates a polarized light beam over a broadband of wavelengths between two alternating orthogonal polarization components. The two orthogonal polarization components of the polarization modulated beam are directed along two distinct optical paths. At least one optical path contains one or more spectral discrimination element, with each spectral discrimination element having spectral absorption features of one or more gases of interest being measured. The two optical paths then intersect, and one orthogonal component of the intersected components is transmitted and the other orthogonal component is reflected. The combined polarization modulated beam is partitioned into one or more smaller spectral regions of interest where one or more gases of interest has an absorption band. The difference in intensity between the two orthogonal polarization components is then determined in each partitioned spectral region of interest as an indication of the spectral emission/absorption of the light beam by the gases of interest in the measurement path. The spectral emission/absorption is indicative of the concentration of the one or more gases of interest in the measurement path. More specifically, one embodiment of the present invention is a gas filter correlation radiometer which comprises a polarizer, a polarization modulator, a polarization beam splitter, a beam combiner, wavelength partitioning element, and detection element. The gases of interest are measured simultaneously and, further, can be measured independently or non-independently. Furthermore, optical or electronic element are provided to balance optical intensities between the two optical paths.
REFERENCES:
patent: 4489239 (1994-12-01), Grant et al.
patent: 4507558 (1985-03-01), Bonne
patent: 4567366 (1986-01-01), Shinohara
patent: 4841149 (1989-06-01), Martin et al.
patent: 4924095 (1990-05-01), Swanson, Jr. et al.
patent: 4963742 (1990-10-01), Abernathy
patent: 4999498 (1991-03-01), Hunt et al.
patent: 5076699 (1991-12-01), Ryan et al.
patent: 5117676 (1992-06-01), Chang
patent: 5128797 (1992-07-01), Sachse et al.
patent: 5134361 (1992-07-01), Pillow
patent: 5162944 (1992-11-01), Yamamoto et al.
patent: 5210702 (1993-05-01), Bishop et al.
patent: 5252828 (1993-10-01), Kert et al.
patent: 5306913 (1994-04-01), Noack et al.
patent: 5319199 (1994-06-01), Stedman et al.
patent: 5343043 (1994-08-01), Johnson et al.
patent: 5343736 (1994-09-01), Cady et al.
patent: 5371367 (1994-12-01), DiDomenico et al.
patent: 5401967 (1995-03-01), Stedman et al.
patent: 5721632 (1998-02-01), Billmers et al.
D. E. Burch and J.D. Penbrook, "Instrument to monitor CH.sub.4, CO, and CO.sub.2 in auto exhaust," Environmental Protection Agency, Washington, DC, EPA Rep. 650/2-73-030, Oct. 1973.
LeBel Peter J.
Rana Mauro
Sachse Glenn W.
Steele Tommy C.
Wang Liang-Guo
Ben Loha
Edwards Robin W.
The United States as represented by the Administrator of the Nat
LandOfFree
Multi-gas sensor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Multi-gas sensor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multi-gas sensor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2386319