Trudeau, Michael E. and Chen, Pin and Garcia, Guilherme de Andrade and Hollberg, Leo W. and Tans, Pieter P. (2006) Stable isotopic analysis of atmospheric methane by infrared spectroscopy by use of diode laser difference-frequency generation. Applied Optics, 45 (17). pp. 4136-4141. ISSN 0003-6935 http://resolver.caltech.edu/CaltechAUTHORS:TRUao06
See Usage Policy.
Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:TRUao06
An infrared absorption spectrometer has been constructed to measure the stable isotopic composition of atmospheric methane samples. The spectrometer employs periodically poled lithium niobate to generate 15 μW of tunable difference-frequency radiation from two near-infrared diode lasers that probe the ν3 rotational-vibrational band of methane at 3.4 μm. To enhance the signal, methane is extracted from 25 l of air by use of a cryogenic chromatographic column and is expanded into the multipass cell for analysis. A measurement precision of 12‰ is demonstrated for both δ13C and δD.
|Additional Information:||© 2006 Optical Society of America Received 14 October 2005; revised 25 January 2006; accepted 26 January 2006; posted 26 January 2006 The authors are grateful to the Environmental Protection Agency (STAR Fellowship); the National Research Council (Postdoctoral Research Associateship Program); and the Fundacão de Amparo a Pesquisa do Estado de São Paulo, Brazil, for financial support of this work. The authors thank E. Dlugokencky at the National Oceanic and Atmospheric Administration’s Earth System Research Laboratory for providing calibrated ambient air samples.|
|Subject Keywords:||Atmospheric composition; nonlinear spectroscopy|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Archive Administrator|
|Deposited On:||16 Oct 2006|
|Last Modified:||26 Dec 2012 09:05|
Repository Staff Only: item control page