Difference-frequency-based tunable absorption spectrometer for detection of atmospheric formaldehyde

D G Lancaster; A Fried; B Wert; B Henry; F K Tittel

doi:10.1364/ao.39.004436

Difference-frequency-based tunable absorption spectrometer for detection of atmospheric formaldehyde

Appl Opt. 2000 Aug 20;39(24):4436-43. doi: 10.1364/ao.39.004436.

Authors

D G Lancaster¹, A Fried, B Wert, B Henry, F K Tittel

Collaborator

F K Tittel²

Affiliations

¹ Electrical and Computer Engineering Department, Rice University, Houston, Texas 77005, USA.
² Rice U, Houston, TX

PMID: 11543547
DOI: 10.1364/ao.39.004436

Abstract

High-sensitivity detection of formaldehyde (CH2O) at 3.5315 micrometers (2831.64 cm-1) is reported with a diode-laser-pumped, fiber-coupled, periodically poled LiNbO3 spectroscopic source. This source replaced the Pb-salt diode laser Dewar assembly of an existing tunable diode-laser absorption spectrometer designed for ultrasensitive detection of CH2O. Spectra are recorded with 2f-modulation spectroscopy and zero-air rapid background subtraction. Initial measurements reported here, determined from multiple measurements of a flowing 7.7 parts per billion by volume (ppbv, parts in 10(9)) CH2O in air mixture, indicate replicate precisions as low as 0.24 ppbv.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Atmosphere / chemistry*
Environmental Monitoring / instrumentation*
Equipment Design
Evaluation Studies as Topic
Formaldehyde / analysis*
Lasers*
Lead
Spectrophotometry, Infrared / instrumentation*

Substances

Formaldehyde
Lead