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J.M. Dai, X.F. Lu, J. Liu, I.C. Ho, N. Karpowicz, and X.-C. Zhang *
Center for Terahertz Research
CII 9009, Rensselaer Polytechnic Institute, Troy, NY 12180-3590 USA
Phone/Fax: (518) 276-3079/3292; web: http://www.rpi.edu/terahertz/
* Email: zhangxc@rpi.edu
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Abstract: Historically, THz technologies were mainly used within the astronomy community for studying cosmic far-infrared radiation background, and by the laser fusion community for the diagnostics of plasmas. Since the first demonstration of THz wave time-domain spectroscopy in the late 80's, there has been a series of significant advances (particularly in recent years) as more intense THz sources and more sensitive detectors provide new opportunities for understanding the basic science in the THz frequency range. Now, the region of the electromagnetic spectrum from 0.3 to 10 THz (1 mm – 30 μm wavelength) is a frontier for research in physics, chemistry, biology, materials science and medicine. Ambient air, when excited with intense femtosecond laser beams, exhibits a remarkable ability to generate and detect pulsed THz waves through an optical nonlinear process. The use of air (or selected gases) as a broadband THz wave emitter and THz wave sensor provides superior bandwidth (0.5 - 20 THz at 10% bandwidth), sensitivity (heterodyne), resolution (<MHz), and the standoff sensing capability in atmosphere which was heretofore considered impossible due to water vapor attenuation. However, research into the basic science and engineering of THz waves in laser-induced air plasma, especially the application of wide-band and high-field THz waves with standoff capability, is just beginning. Our proposed instrumentation development explores this new area, with an emphasis on broadband spectroscopy, remote sensing and nonlinear effect.
Keywords: Terahertz generation, THz detection, THz spectroscopy, Nonlinear optics, Air photonics, Remote sensing.
Published: 2009-12-30
Acknowledgments: We gratefully acknowledge support from the United State National Science Foundation, the Defense Threat Reduction Agency, the Office of Naval Research, and the Department of Homeland Security through the DHS-ALERT Center under Award No. 2008-ST-061-ED0001. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Department of Homeland Security.
Cite this article:
J.M. Dai, X.F. Lu, J. Liu, I.C. Ho, N. Karpowicz, and X.-C. Zhang. Remote THz Wave Sensing in Ambient Atmosphere[J]. International Journal of Terahertz Science and Technology, 2009, Vol.2, No.4: 131-143. DOI:10.11906/TST.131-143.2009.12.14
URL: http://www.tstnetwork.org/10.11906/TST.131-143.2009.12.14
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