Open AccessHighly efficient all-optical beam modulation utilizing thermo-optic effects
Author(s) -
Vladimir Liberman,
Paul D. Robinson,
G. Geurtsen,
Shane Tysk,
M. W. Geis
Publication year - 2018
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.009502
Subject(s) - materials science , optics , nanoparticle , phase modulation , diffraction , beam (structure) , modulation (music) , decane , diffraction efficiency , optical force , laser , plasmonic nanoparticles , optical tweezers , chemistry , physics , nanotechnology , phase noise , acoustics , organic chemistry
Suspensions of plasmonic nanoparticles can diffract optical beams due to the combination of thermal lensing and self-phase modulation. Here, we demonstrate extremely efficient optical continuous wave (CW) beam switching across the visible range in optimized suspensions of 5-nm Au and Ag nanoparticles in non-polar solvents, such as hexane and decane. On-axis modulation of greater than 30 dB is achieved at incident beam intensities as low as 100 W/cm 2 with response times under 200 μs, at initial solution transparency above 70%. No evidence of laser-induced degradation is observed for the highest intensities used. Numerical modeling of experimental data reveals thermo-optic coefficients of up to -1.3 × 10 -3 /K, which, to our knowledge, is the highest observed to date in such nanoparticle suspensions.