Water-Vapor Detection Using Asynchronous THz Sampling
Authors: Brown, Michael S.1; Fiechtner, Gregory J.2; Rudd, J.V.3; Zimdars, David A.4; Warmuth, Matthew5; Gord, James R.6
Source: Applied Spectroscopy, Volume 60, Issue 3, Pages 62A-90A and 229-345 (March 2006) , pp. 261-265(5)
Publisher: Society for Applied Spectroscopy
Abstract:
The use of a fiber-coupled terahertz (THz) transmitter/receiver pair for spectroscopic detection of water vapor is investigated. Transmission signals of an alumina cylinder demonstrate that the measurement approach can be applied in a windowless ceramic combustor. First, a conventional commercial transmitter/receiver pair is used to make measurements for frequencies to 1.25 THz. Water-vapor absorption is clearly evident within the alumina transparency window and is readily modeled using existing databases. A variety of data-acquisition schemes is possible using THz instrumentation. To assess signal-collection techniques, a prototype THz transmitter/receiver pair is then used with the asynchronous optical-sampling (ASOPS) technique to obtain asynchronous THz-sampling signals to 1 THz without the need for an optomechanical delay line. Two mode-locked Ti:sapphire lasers operating at slightly different repetition rates are used for pumping the transmitter and receiver independently to permit a complete time-domain THz signal to be recorded. The resulting repetitive phase walkout is demonstrated by collecting power spectra of room air that exhibit water-vapor absorption.Keywords: TERAHERTZ TIME-DOMAIN SPECTROSCOPY; THZ-TDS; ASYNCHRONOUS OPTICAL SAMPLING; ASOPS; WATER VAPOR
Document Type: Research article
DOI: http://dx.doi.org/10.1366/000370206776342670
Affiliations: 1: Innovative Scientific Solutions, Inc., 2766 Indian Ripple Road, Dayton, Ohio 45440-3638 2: Sandia National Laboratories, P.O. Box 969, Livermore, California 94550-0969 3: Picometrix, Inc., 2925 Boardwalk, Ann Arbor, Michigan 48104-6765; Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87123-1153 4: Picometrix, Inc., 2925 Boardwalk, Ann Arbor, Michigan 48104-6765 5: Picometrix, Inc., 2925 Boardwalk, Ann Arbor, Michigan 48104-6765; General Dynamics, P.O. Box 134008, Ann Arbor, MI 48113-4008 6: Air Force Research Laboratory, Propulsion Directorate, Wright-Patterson AFB, Ohio 45433-7251
Publication date: 2006-03-01
- The Society publishes the internationally recognized, peer reviewed journal, Applied Spectroscopy, which is available both in print and online. Subscriptions are included with membership or can be purchased by institutional or corporate organizations. Abstracts may be viewed free of charge. Previously published as Bulletin (Society for Applied Spectroscopy)
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Request copyrighted SAS materials
- Spectroscopic Nomenclature
- Focus Compendium
- ingentaconnect is not responsible for the content or availability of external websites
- In this: publication
- By this: publisher
- In this Subject: Analytical Chemistry
- By this author: Brown, Michael S. ; Fiechtner, Gregory J. ; Rudd, J.V. ; Zimdars, David A. ; Warmuth, Matthew ; Gord, James R.

Shopping cart
Receive new issue alert
Get Permissions