Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Stable isotopic analysis of atmospheric methane by infrared spectroscopy by use of diode laser difference-frequency generation

Published

Author(s)

M. E. Trudeau, Pin Chen, G de Andreade Garcia, Leo W. Hollberg, P P. Tans

Abstract

An infrared absorption spectrometer has been constructed to measure the stable isotopic composition of atmospheric methane samples. The spectrometer employs periodically poled lithium niobate (PPLN) to generate 15 W of tunable difference frequency radiation from two near infrared diode lasers that probes the 3 rotational-vibrational band of methane at 3.4 microns. To enhance the signal, methane is extracted from 25 L of air using a cryogenic chromatographic column and is expanded into the multipass cell for analysis. A measurement precision of 12? is demonstrated for both ?13C and ?D.
Citation
Applied Optics
Volume
45
Issue
17

Keywords

air, difference frequency generation, infrared, isotopes, methane, periodically poled lithium niobate, spectroscopy

Citation

Trudeau, M. , Chen, P. , de, G. , Hollberg, L. and Tans, P. (2006), Stable isotopic analysis of atmospheric methane by infrared spectroscopy by use of diode laser difference-frequency generation, Applied Optics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50190 (Accessed May 30, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created June 10, 2006, Updated February 17, 2017