Accession Number : ADA582397


Title :   Photoacoustic Detection of Terahertz Radiation for Chemical Sensing and Imaging Applications


Descriptive Note : Master's thesis


Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT


Personal Author(s) : Blazevic, Stjepan


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a582397.pdf


Report Date : Mar 2013


Pagination or Media Count : 202


Abstract : The main research objective is the development of photoacoustic sensor capable of detecting weak terahertz (THz) electromagnetic radiation. The feasibility of THz remote sensing is seen in the utilization of Microelectromechanical systems (MEMS) cantilever-based sensor. The overall sensing functionality of the detector in development is based on the photoacoustic spectroscopy and direct piezoelectric effect phenomena, as a result of which significant part of investigation has been conducted in the areas of terahertz electromagnetic radiation and its detection. The main focus of this research work was the detector analytical and Finite Element Method (FEM) simulation modeling, involving necessary material properties investigations and adequate selections which were, beside the sensors' geometry considerations, heavily engaged in the device modeling. Five different MEMS detector configurations have been analyzed and modeled as potential THz photoacoustic sensing options: Three configurations of rectangular shape, single piezoelectric layer cantilever-based sensors, Circular membrane sensing configuration and Square membrane sensing configuration. Some level of disagreement was discovered between the analytical and FEM simulated results, which has been analyzed and possible reasons were established. The obtained results indicated that the Square membrane has demonstrated the ability to respond effectively to any radiation level from the entire THz photoacoustic range exhibiting high sensitivity and thus was selected as the best terahertz photoacoustic sensing solution.


Descriptors :   *CHEMICAL DETECTION , *IMAGES , *RADIATION , FINITE ELEMENT ANALYSIS , MICROELECTROMECHANICAL SYSTEMS


Subject Categories : Astrophysics
      Miscellaneous Detection and Detectors
      Optics


Distribution Statement : APPROVED FOR PUBLIC RELEASE