Share Email Print
cover

Proceedings Paper

Evolution of THz impulse imaging radar to 1550nm photoconductive switches
Author(s): E. R. Brown; W.-D. Zhang; A. Feldman; T. Harvey; R. P. Mirin; S. Sung; W. S. Grundfest; Z. D. Taylor
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

We present measurements of sub-bandgap photoconductivity and photoconductive switches using GaAs doped heavily with Er such that nanoparticles of ErAs are formed. In addition to strong resonant absorption centered around 1550 nm, the material provides strong sub-bandgap photoconductivity and >> μW average power levels when fabricated into an efficient (square spiral) THz antenna and driven by a 1550- nm ultrafast fiber laser. Photo-Hall measurements prove that the predominant photocarrier is the electron and the linearity of the 1550-nm photocurrent (with laser power) suggests that the photoconductivity is “extrinsic”, not other possible mechanisms, such as two-photon absorption. These results have immediate relevance to the use of GaAs:Er switches as the transmitter in 1550-nm-driven THz imaging systems such as the “impulse imager” that we have successfully used for biomedical imaging applications.

Paper Details

Date Published: 26 May 2016
PDF: 10 pages
Proc. SPIE 9854, Image Sensing Technologies: Materials, Devices, Systems, and Applications III, 98540L (26 May 2016); doi: 10.1117/12.2224919
Show Author Affiliations
E. R. Brown, Wright State Univ. (United States)
W.-D. Zhang, Wright State Univ. (United States)
A. Feldman, National Institute of Standards and Technology (United States)
T. Harvey, National Institute of Standards and Technology (United States)
R. P. Mirin, National Institute of Standards and Technology (United States)
S. Sung, Univ. of California, Los Angeles (United States)
W. S. Grundfest, Univ. of California, Los Angeles (United States)
Z. D. Taylor, Univ. of California, Los Angeles (United States)


Published in SPIE Proceedings Vol. 9854:
Image Sensing Technologies: Materials, Devices, Systems, and Applications III
Nibir K. Dhar; Achyut K. Dutta, Editor(s)

© SPIE. Terms of Use
Back to Top