Deflecting light into resonant cavities for spectroscopy

Patent · Thu Jan 01 00:00:00 EST 1998

OSTI ID:871873

Zare, Richard N ^[1]; Martin, Juergen ^[2]; Paldus, Barbara A ^[1]

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1. Stanford, CA
2. Harxheim, DE

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.

• Research Organization: Stanford Univ., CA (United States)
• DOE Contract Number: FG03-92ER14304
• Assignee: Board of Trustees of Leland Stanford Junior Univesity (Stanford, CA)
• Patent Number(s): US 5815277
• OSTI ID: 871873
• Country of Publication: United States
• Language: English

Related Subjects

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
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