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Title: Deflecting light into resonant cavities for spectroscopy

Abstract

Light is coupled into a cavity ring down spectroscopy (CRDS) resonant cavity using an acousto-optic modulator. The AOM allows in-coupling efficiencies in excess of 40%, which is two to three orders of magnitude higher than in conventional systems using a cavity mirror for in-coupling. The AOM shutoff time is shorter than the roundtrip time of the cavity. The higher light intensities lead to a reduction in shot noise, and allow the use of relatively insensitive but fast-responding detectors such as photovoltaic detectors. Other deflection devices such as electro-optic modulators or elements used in conventional Q-switching may be used instead of the AOM. The method is particularly useful in the mid-infrared, far-infrared, and ultraviolet wavelength ranges, for which moderately reflecting input mirrors are not widely available.

Inventors:
 [1];  [2];  [1]
  1. Stanford, CA
  2. Harxheim, DE
Issue Date:
Research Org.:
Stanford Univ., CA (United States)
OSTI Identifier:
871873
Patent Number(s):
5815277
Assignee:
Board of Trustees of Leland Stanford Junior Univesity (Stanford, CA)
Patent Classifications (CPCs):
G - PHYSICS G01 - MEASURING G01J - MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED, VISIBLE OR ULTRA-VIOLET LIGHT
G - PHYSICS G01 - MEASURING G01N - INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
DOE Contract Number:  
FG03-92ER14304
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
deflecting; light; resonant; cavities; spectroscopy; coupled; cavity; crds; acousto-optic; modulator; aom; allows; in-coupling; efficiencies; excess; 40; magnitude; conventional; systems; mirror; shutoff; time; shorter; roundtrip; intensities; lead; reduction; shot; noise; allow; relatively; insensitive; fast-responding; detectors; photovoltaic; deflection; devices; electro-optic; modulators; elements; q-switching; method; particularly; useful; mid-infrared; far-infrared; ultraviolet; wavelength; ranges; moderately; reflecting; input; mirrors; widely; available; resonant cavities; light intensities; wavelength range; particularly useful; resonant cavity; ultraviolet wavelength; trip time; acousto-optic modulator; relatively insensitive; wavelength ranges; cavity mirror; electro-optic modulator; /356/

Citation Formats

Zare, Richard N, Martin, Juergen, and Paldus, Barbara A. Deflecting light into resonant cavities for spectroscopy. United States: N. p., 1998. Web.
Zare, Richard N, Martin, Juergen, & Paldus, Barbara A. Deflecting light into resonant cavities for spectroscopy. United States.
Zare, Richard N, Martin, Juergen, and Paldus, Barbara A. Thu . "Deflecting light into resonant cavities for spectroscopy". United States. https://www.osti.gov/servlets/purl/871873.
@article{osti_871873,
title = {Deflecting light into resonant cavities for spectroscopy},
author = {Zare, Richard N and Martin, Juergen and Paldus, Barbara A},
abstractNote = {Light is coupled into a cavity ring down spectroscopy (CRDS) resonant cavity using an acousto-optic modulator. The AOM allows in-coupling efficiencies in excess of 40%, which is two to three orders of magnitude higher than in conventional systems using a cavity mirror for in-coupling. The AOM shutoff time is shorter than the roundtrip time of the cavity. The higher light intensities lead to a reduction in shot noise, and allow the use of relatively insensitive but fast-responding detectors such as photovoltaic detectors. Other deflection devices such as electro-optic modulators or elements used in conventional Q-switching may be used instead of the AOM. The method is particularly useful in the mid-infrared, far-infrared, and ultraviolet wavelength ranges, for which moderately reflecting input mirrors are not widely available.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1998},
month = {1}
}

Works referenced in this record:

CW cavity ring down spectroscopy
journal, January 1997