Measurement and modeling of rough surface effects on terahertz spectroscopy

S. C. Henry; S. Schecklman; G. P. Kniffin; L. M. Zurk; A. Chen

doi:10.1117/12.841054

18 February 2010 Measurement and modeling of rough surface effects on terahertz spectroscopy

S. C. Henry, S. Schecklman, G. P. Kniffin, L. M. Zurk, A. Chen

Proceedings Volume 7601, Terahertz Technology and Applications III; 760108 (2010) https://doi.org/10.1117/12.841054
Event: SPIE OPTO, 2010, San Francisco, California, United States

Abstract

Recent improvements in sensing technology have driven new research areas within the terahertz (THz) portion of the electromagnetic (EM) spectrum. While there are several promising THz applications, several outstanding technical challenges need to be addressed before robust systems can be deployed. A particularly compelling application is the potential use of THz reflection spectroscopy for stand-off detection of drugs and explosives. A primary challenge for this application is to have sufficient signal-to-noise ratio (SNR) to allow spectroscopic identification of the target material, and surface roughness can have an impact on identification. However, scattering from a rough surface may be observed at all angles, suggesting diffuse returns can be used in robust imaging of non-cooperative targets. Furthermore, the scattering physics can also distort the reflection spectra, complicating classification algorithms. In this work, rough surface scattering effects were first isolated by measuring diffuse scattering for gold-coated sandpaper of varying roughness. Secondly, we measured scattering returns from a rough sample with a spectral signature, namely α-lactose monohydrate mixed with Teflon and pressed with sandpaper to introduce controlled roughness. For both the specular and diffuse reflection measurements, the application of traditional spectroscopy techniques provided the ability to resolve the 0.54 THz absorption peak. These results are compared with results from a smooth surface. Implications of the results on the ability to detect explosives with THz reflection spectroscopy are presented and discussed. In addition, the Small Perturbation Method (SPM) is employed to predict backscatter from lactose with a small amount of roughness.

Citation Download Citation

S. C. Henry, S. Schecklman, G. P. Kniffin, L. M. Zurk, and A. Chen "Measurement and modeling of rough surface effects on terahertz spectroscopy", Proc. SPIE 7601, Terahertz Technology and Applications III, 760108 (18 February 2010); https://doi.org/10.1117/12.841054

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available