Abstract-Photoconductive generation and detection of THz-bandwidth pulses using near-field coupling to a free-space metallic slit waveguide

Robert Smith, Afshin Jooshesh, Jinye Zhang, and Thomas Darcie

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-25-22-26492&origin=search

THz-bandwidth pulses are generated, transmitted along a gold-plated stainless steel metallic slit waveguide, and detected with 1.5 THz bandwidth and 60 dB dynamic range. The source and detector were edge-pumped slotlines on LT-GaAs placed within the near-field region of the waveguide entrance and exit aperture. The motivation for this work was to develop a complete dispersion-free THz system which was simple to manufacture and could be utilized for free-space waveguide experimentation.

© 2017 Optical Society of America

Abstract-THz-TDS using a photoconductive free-space linear tapered slot antenna transmitter

Robert Smith, Afshin Jooshesh, Jinye Zhang, and Thomas Darcie

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-25-9-10118

A near-field edge-coupled photoconductive free-space linear tapered slot antenna has been constructed as a planar alternative to the standard photoconductive switch coupled to a silicon substrate lens. The temporal response along the optical axis is investigated to ensure the structure itself does not introduce pulse distortion which would fundamentally limit the usefulness of the structure. Experimental results show that a 1.6 THz bandwidth with a ≈50dB dynamic range is achievable with the new structure which is comparable to our reference experiment with a standard silicon substrate lens. The investigated structure has the added benefit of a potential substantial physical size reduction and can also be used to excite waveguides in the near-field.

© 2017 Optical Society of America

Abstract-Plasmon-Enhanced below Bandgap Photoconductive Terahertz Generation and Detection

Afshin Jooshesh, Vahid Bahrami-Yekta, Jinye Zhang, Thomas Tiedje, Thomas E. Darcie, andReuven Gordon*

Department of Electrical and Computer Engineering, University of Victoria, Victoria, British Columbia V8P 5C2, Canada

Nano Lett., Article ASAP

DOI: 10.1021/acs.nanolett.5b03922

Publication Date (Web): November 17, 2015

Copyright © 2015 American Chemical Society

*E-mail: rgordon@uvic.ca.

http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.5b03922

We use plasmon enhancement to achieve terahertz (THz) photoconductive switches that combine the benefits of low-temperature grown GaAs with mature 1.5 μm femtosecond lasers operating below the bandgap. These below bandgap plasmon-enhanced photoconductive receivers and sources significantly outperform commercial devices based on InGaAs, both in terms of bandwidth and power, even though they operate well below saturation. This paves the way for high-performance low-cost portable systems to enable emerging THz applications in spectroscopy, security, medical imaging, and communication.