UVicSpace

Enhancing terahertz photoconductive switches using nanotechnology

Show simple item record

dc.contributor.author Heshmat Dehkordi, Barmak
dc.date.accessioned 2013-03-27T20:04:15Z
dc.date.available 2014-03-02T12:22:03Z
dc.date.copyright 2012 en_US
dc.date.issued 2013-03-27
dc.identifier.uri http://hdl.handle.net/1828/4498
dc.description.abstract In this thesis we use three main approaches to enhance the performance of terahertz photoconductive switches (THz PC switches). We first propose two novel materials (GaBiAs and carbon nanotubes) for the substrate. The resulting enhancement in THz emission and reception are significant for GaBiAs. As thoroughly analyzed and addressed in Chapter 2, both the emission bandwidth and the emission amplitude of the device are improved by these materials. A systematic study of CNTs predicts 2 orders of magnitude enhancement in THz emission and one order of magnitude enhancement in THz reception. Experimental results for GaBiAs indicate 0.5 THz increase in bandwidth and 68% increase in the emitted THz wave amplitude. The bandwidth enhancement is in comparison to premium commercial devices. The optical excitation of the PC switch is studied and optimized next as the second enhancement approach (Chapter 3). The study presented in Chapter 3 provides an insight on the subwavelength dynamics of the optical excitation E-field at the edge of the electrodes. The study reveals that majority of the fast photocarriers are collected at the edge of the electrode in a subwavelength scale area. This insight leads to optimization of illumination profile and also the third enhancement approach, namely, the enhancement of electrode structure (Chapter 4). In Chapter 4 we have engineered the electrodes down to nanometer scale. This significantly enhances the optical excitation of the substrate and also overcomes the undesired properties of some substrate materials such as long carrier lifetime. Fabricated devices and fabrication processes are assessed in Chapter 5. Results (Chapter 6) highlight more than two orders of magnitude enhancement for nanostructures on GaAs. en_US
dc.language English eng
dc.language.iso en en_US
dc.subject Terahertz waveguides en_US
dc.subject Nanotechnology en_US
dc.subject Carbon nanotubes en_US
dc.subject TRTS en_US
dc.subject Nanoplasmonic en_US
dc.subject Photoconductive switch en_US
dc.subject Photomixer en_US
dc.subject GaAs en_US
dc.subject GaAsBi en_US
dc.title Enhancing terahertz photoconductive switches using nanotechnology en_US
dc.type Thesis en_US
dc.contributor.supervisor Darcie, Thomas Edward
dc.degree.department Dept. of Electrical and Computer Engineering en_US
dc.degree.level Doctor of Philosophy Ph.D. en_US
dc.rights.temp Available to the World Wide Web en_US
dc.identifier.bibliographicCitation B. Heshmat, H. Pahlevaninezhad,Y. Pang, M. Masnadi, R. Lewis, T. Tiedje, R. Gordon and T. E. Darcie "Nanoplasmonic terahertz photoconductive switch on GaAs",Nanoletter, Vol. 12, Iss.12, pp.6255–6259 (2012). en_US
dc.identifier.bibliographicCitation B. Heshmat, H. Pahlevaninezhad, and T.E. Darcie "THz detection with carbon nanotube based photoconductive switches: An assessment of capabilities and limitations", IEEE Photonics Journal, Vol. 4, Iss. 3, pp.970-985,(2012). en_US
dc.identifier.bibliographicCitation B. Heshmat, H. Pahlevaninezhad, M. C. Beard,C. Papadopoulos and T.E. Darcie,"Single wall carbon nanotubes as base material for THz photomixing: A Theoretical study from input power to output THz emssion", Optics Express, Vol. 19, Iss. 16, pp.15077-15089 (2011). en_US
dc.identifier.bibliographicCitation B. Heshmat, D. Li, T. E. Darcie, R. Gordon, " Tuning plasmonic resonances of an annular aperture in metal plate " Optics Express, Vol. 19, Iss. 7, pp. 5912–5923 (2011). en_US
dc.identifier.bibliographicCitation H. Pahlevaninezhad, B. Heshmat, T. E. Darcie, Fellow, IEEE, "Advances in THz technology", IEEE Photonics, Vol. 3, Iss. 2, pp. 307-310, 2011. en_US
dc.identifier.bibliographicCitation H. Pahlevaninezhad, B. Heshmat and T. E. Darcie "Efficient THz slotline waveguides" Optics Express, Vol. 19 Iss. 26, pp.B47-B55 (2011) en_US
dc.description.scholarlevel Graduate en_US
dc.description.proquestcode 0544 en_US


Files in this item

This item appears in the following Collection(s)

Show simple item record

Search UVicSpace


Browse

My Account

Statistics

Help