Abstract
We investigate single-cycle terahertz (THz) field-induced
nonlinear
absorption in doped silicon carbide. We find that the nonlinear response
is ultrafast, and we observe up to 20% reduction of transmission of
single THz pulses at peak field strengths of 280 kV/cm. We model the
field and temperature dependence of the nonlinear response by a finite-difference
time-domain simulation that incorporates the temporally nonlocal nonlinear
conductivity of the silicon carbide. Nonlinear two-dimensional THz
spectroscopy reveals that the nonlinear absorption has an ultrafast
subpicosecond recovery time, with contributions from both sum-frequency
generation and four-wave mixing, in the form of a photon-echo signal.
The ultrafast nonlinearity with its equally fast recovery time makes
silicon carbide an interesting candidate material for extremely fast
nonlinear THz modulators.
Original language | English |
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Journal | ACS Photonics |
Volume | 7 |
Issue number | 1 |
Pages (from-to) | 221-231 |
ISSN | 2330-4022 |
DOIs | |
Publication status | Published - 2019 |