In situ supercontinuum nanopatterning of silicon surface by femtosecond laser super-filaments
S. I. Kudryashov+*, L. V. Seleznev+, A. A. Rudenko+, A. A. Ionin+
+Lebedev Physical Institute, 119991 Moscow, Russia
*National Research Nuclear University MEPhI, 115409 Moscow, Russia
Abstract
We for the first time theoretically predict and experimentally demonstrate that
selective, low-threshold excitation and interference between short-wavelength plasmons on
silicon surfaces photoexcited by infrared femtosecond laser pulses give rise to appearance of
permanent sub-diffraction surface gratings with their periods down to 100 nm,
dramatically differing from near-wavelength surface gratings succeeding the common
"laser photon-surface polariton" interference. Such selectivity was provided in this work
by in situ/ white-light (supercontinuum) femtosecond source generated in a
multi-filamentation regime in a thin water layer atop the silicon surface, supporting
high-efficiency excitation and dynamic tracking of the transiently tunable plasmon resonance
on silicon surface for its easy, robust and ultimate surface nanopatterning.