Thomas G Spence

US Patent:

6532071, Mar 11, 2003

Filed:

Jan 4, 2001

Appl. No.:

09/755253

Inventors:

Richard N. Zare - Stanford CA
Charles C. Harb - Palo Alto CA
Barbara A. Paldus - Mountain View CA
Thomas G. Spence - Palo Alto CA

Assignee:

The Board of Trustees of the Leland Stanford Junior University - Stanford CA

International Classification:

G01N 2117

US Classification:

356437, 356440, 250343

Abstract:

An analog detection system for determining a ring-down rate or decay rate 1/ of an exponentially decaying ring-down beam issuing from a lifetime or ring-down cavity during a ring-down phase. Alternatively, the analog detection system determines a build-up rate of an exponentially growing beam issuing from the cavity during a ring-up phase. The analog system can be employed in continuous wave cavity ring-down spectroscopy (CW CRDS) and pulsed CRDS (P CRDS) arrangements utilizing any type of ring-down cavity including ring-cavities and linear cavities.

US Patent:

20130144561, Jun 6, 2013

Filed:

Aug 19, 2011

Appl. No.:

13/809569

Inventors:

Charles Charbel Harb - Bungendore, AU
Thomas Gary Spence - New Orleans LA, US
Toby Kristian Boyson - Conder, AU

Assignee:

NewSouth Innovations Pty Limited - New South Wales

International Classification:

G01N 21/59
G06F 17/00

US Classification:

702189

Abstract:

Systems and methods for analysing a time-domain signal are described. The method comprising: in a mixer (), mixing the time-decay signal () with a local oscillator signal () generated by a local oscillator (), resulting in a mixed signal from which a Fourier transformed time-decay signal is generated comprising a fundamental transformed time decay signal at the fundamental frequency of the local oscillator signal () and a plurality of transformed time-decay signals at a plurality of frequencies; and determining the magnitude of each of the transformed time-decay signals at the fundamental frequency and at a frequency other than the fundamental frequency.

US Patent:

62330527, May 15, 2001

Filed:

Mar 19, 1999

Appl. No.:

9/273195

Inventors:

Richard N. Zare - Stanford CA
Charles C. Harb - Palo Alto CA
Barbara A. Paldus - Mountain View CA
Thomas G. Spence - Palo Alto CA

Assignee:

The Board of Trustees of the Leland Stanford Junior University - Stanford CA

International Classification:

G01N 2100
G01J 502

US Classification:

356437

Abstract:

An analog detection system for determining a ring-down rate or decay rate 1/. tau. of an exponentially decaying ring-down beam issuing from a lifetime or ring-down cavity during a ring-down phase. Alternatively, the analog detection system determines a build-up rate of an exponentially growing beam issuing from the cavity during a ring-up phase. The analog system can be employed in continuous wave cavity ring-down spectroscopy (CW CRDS) and pulsed CRDS (P CRDS) arrangements utilizing any type of ring-down cavity including ring-cavities and linear cavities.

US Patent:

60846828, Jul 4, 2000

Filed:

Apr 15, 1998

Appl. No.:

9/061080

Inventors:

Richard N. Zare - Stanford CA
Barbara A. Paldus - Stanford CA
Charles C. Harb - Palo Alto CA
Thomas Spence - Union City CA

Assignee:

The Board of Trustees of the Leland Stanford Junior University - Palo Alto CA

International Classification:

G01N 2100

US Classification:

356437

Abstract:

Distinct locking and sampling light beams are used in a cavity ring-down spectroscopy (CRDS) system to perform multiple ring-down measurements while the laser and ring-down cavity are continuously locked. The sampling and locking light beams have different frequencies, to ensure that the sampling and locking light are decoupled within the cavity. Preferably, the ring-down cavity is ring-shaped, the sampling light is s-polarized, and the locking light is p-polarized. Transmitted sampling light is used for ring-down measurements, while reflected locking light is used for locking in a Pound-Drever scheme.