Andrew A Mills

US Patent:

20140264031, Sep 18, 2014

Filed:

Feb 12, 2014

Appl. No.:

14/178985

Inventors:

- Ann Arbor MI, US
Kevin F. Lee - Ann Arbor MI, US
Andrew A. Mills - Ann Arbor MI, US

Assignee:

IMRA AMERICA, INC. - Ann Arbor MI

International Classification:

G01J 3/42
A61B 5/00
G01J 3/10

US Classification:

25033902, 25033908, 25033907

Abstract:

The present invention relates to a trace gas detection system. At least one embodiment includes a frequency spectrum comprising a 1st comb and an enhancement cavity characterized by having a 2comb of spectral resonances. The enhancement cavity contains a sample gas for spectroscopic measurement. A dither mechanism is configured to modulate the relative spectral position between the combs at a dither frequency, f. The dither mechanism, in conjunction with a feedback mechanism, stabilizes the location of said 1comb lines with respect to the resonances of said 2comb over a time scale much greater than a dither period, T=1/f. A time-averaged output from the enhancement cavity is provided to a spectroscopic measurement tool, for example a Fourier transform spectrometer. The system is capable of detecting volatile organic compounds, endogenous compounds, and may be configured for cancer detection.