Laser-induced thermal acoustics: simple accurate gas measurements

Laser-induced thermal acoustics (LITA), an optical four-wave mixing technique, has been used for sensitive measurement of the sound speed, thermal diffusivity, acoustic damping rate, and complex susceptibility of a gas. In LITA, laser-induced acoustic waves scatter laser light into a coherent, modul...

Full description

Saved in:
Bibliographic Details
Published in:Optics letters 1994-09, Vol.19 (17), p.1361-1363
Main Author: Cummings, E B
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Laser-induced thermal acoustics (LITA), an optical four-wave mixing technique, has been used for sensitive measurement of the sound speed, thermal diffusivity, acoustic damping rate, and complex susceptibility of a gas. In LITA, laser-induced acoustic waves scatter laser light into a coherent, modulated signal beam. A simple expression accurately describes the signal. Atmospheric sound speeds accurate to 0.5% and transport properties accurate to 30% have been measured in a single shot without calibration. LITA spectra have been taken of weak spectral lines of NO(2) in concentrations of less than 50 parts in 10(9). Signal reflectivities up to 10(-4) are estimated.
ISSN:0146-9592
1539-4794
DOI:10.1364/ol.19.001361