Generation of terahertz radiation by optical excitation of aligned carbon nanotubes

Lyubov V Titova; Cary L Pint; Qi Zhang; Robert H Hauge; Junichiro Kono; Frank A Hegmann

doi:10.1021/acs.nanolett.5b00494

Generation of terahertz radiation by optical excitation of aligned carbon nanotubes

Nano Lett. 2015 May 13;15(5):3267-72. doi: 10.1021/acs.nanolett.5b00494. Epub 2015 Apr 20.

Authors

Lyubov V Titova^{1

2}, Cary L Pint³, Qi Zhang, Robert H Hauge, Junichiro Kono, Frank A Hegmann¹

Affiliations

¹ †Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada.
² ‡Department of Physics, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, United States.
³ §Department of Mechanical Engineering, Vanderbilt University, Nashville, Tennessee 37240, United States.

PMID: 25879274
DOI: 10.1021/acs.nanolett.5b00494

Abstract

We have generated coherent pulses of terahertz radiation from macroscopic arrays of aligned single-wall carbon nanotubes (SWCNTs) excited by femtosecond optical pulses without externally applied bias. The generated terahertz radiation is polarized along the SWCNT alignment direction. We propose that top-bottom asymmetry in the SWCNT arrays produces a built-in electric field in semiconducting SWCNTs, which enables generation of polarized terahertz radiation by a transient photocurrent surge directed along the nanotube axis.

Keywords: SWCNTs; Single-wall carbon nanotubes; THz pulses; terahertz generation.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.