Cavity-locked ring down spectroscopy

US6084682A · kind A · utility

Assignee

• The Board of Trustees of the Leland Stanford Junior University · US

Inventors

• Richard N. Zare · Stanford, US
• Barbara Paldus · Atherton, US
• Charles Charbel Harb · Palo Alto, US
• Thomas G. Spence · Palo Alto, US

Key dates

• Filing date: Apr 15, 1998
• Grant date: Jul 4, 2000
• Expiry date: Apr 15, 2018

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2021/391
• WIPO field: Measurement
• WIPO sector: Instruments

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.