Optics: measuring and testing – For light transmission or absorption – Of fluent material
Patent
1998-05-21
2000-07-18
Hantis, K. P.
Optics: measuring and testing
For light transmission or absorption
Of fluent material
250343, 356409, G01N 2100
Patent
active
060915048
ABSTRACT:
A system and method for determining the concentration of an analyte such as oxygen in an unknown gas sample. A Vertical Cavity Surface Emitting Laser (VCSEL) is used as a variable wavelength light source which is "swept" through a wavelength range by varying the drive signal applied thereto. Quantitative spectroscopic analysis of the unknown gas sample is performed without the requirement of feedback circuitry for tuning the light source to the characteristic frequency of an analyte. Instead, the VCSEL is repeatedly "swept" through a range of frequencies determined by the drive signal, and the absorption is measured by the detector. The absorption lines do not always occur at the same place but instead move along around during the sweep based on the temperature and baseline current. The absorption at a particular wavelength may be determined by overlaying the drive signal and its timing information over the detected absorption signal.
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Braig James R.
Curnan William A.
Goldberger Daniel S.
Nichols Robert A.
Svai Sophat
Hantis K. P.
Square One Technology, Inc.
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