Showing posts with label Robert Smith. Show all posts
Showing posts with label Robert Smith. Show all posts

Tuesday, November 21, 2017

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

Tuesday, April 25, 2017

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