The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 27, 2004
Filed:
Jan. 12, 2001
Applicant:
Inventors:
Jun Ye, Louisville, CO (US);
John L. Hall, Boulder, CO (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01J 1/04 ;
U.S. Cl.
CPC ...
G01J 1/04 ;
Abstract
An ac technique for cavity ringdown spectroscopy permits 1×10 absorption sensitivity with microwatt light power. Two cavity modes are provided temporally out of phase such that when one mode is decaying, the other mode is rising. When one of the modes probes intra-cavity absorption of a sample gas, heterodyne detection between the two modes reveals dynamic time constants associated with the cavity and the cavity plus intra-cavity absorption. The system and method provides a quick comparison between on-resonance and off-resonance modes and enables sensitivities that approach the shot-noise limit.