Research Areas
Nanophotonics & Nanoplasmonics
Reseach topics
Single nanohole & photonic crystal
Single
nanohole as nonlinear element
Publications
Single nanohole as an effective nonlinear optical element
A new element for nanooptics and nanoplasmonics: Split Hole Resonator (SHR)
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We propose
and experimentally realize a new element for nanoplasmonics - a split
hole resonator (SHR). The SHR is the marriage of two basic elements of
nanoplasmonics, a nanohole and a nanorod (Fig.1). A peak field
intensity in the SHR occurs at the single tip of
the nanorod inside the nanohole. The peak field is much stronger than
those of the nanorod and nanohole, because the SHR field involves
contributions from the following two field-enhancement mechanisms: (1)
the excitation of surface plasmon resonances and (2) the lightning-rod
effect. Here, we demonstrate the use of the SHR as a highly efficient
nonlinear optical element for: (i) the generation of the third harmonic
from a single SHR; (ii) the excitation of intense multiphoton
luminescence from a single SHR; (iii) the construction of a
polarization-ultrasensitive nanoelement; and finally, as a practical
application, (iv) the building up of an all-optical display. References: |
 Generation of the third harmonic by an SHR nanostructure formed in aluminum film. (a) an electron microscope image of the nanostructure formed by a nanohole of 380 nm diameter and nanorod of 220 nm (length) × 120 nm (width), (b) calculated enhancement of the electric field amplitude upon irradiation of the nanostructure of Fig. 3(a) by a plane monochromatic wave with a wavelength of 1560 nm, (c) an optical image of the nanostructure upon its laser irradiation at a wavelength of 1560 nm and detection at the THG wavelength, and (d) measured spectrum of radiation that forms optical image presented on Fig. 3(c) . The incident radiation is polarized along the direction of the nanorod of the nanostructure. |
We
realize
giant optical nonlinearity of a single plasmonic nanostructure which we
call a split hole resonator (SHR). The SHR is the marriage of two basic
elements of nanoplasmonics, a nanohole and a nanorod. A peak field
intensity in the SHR occurs at the single tip of
the nanorod inside the nanohole. The peak field is much stronger than
those
of the nanorod and nanohole, because the SHR field involves
contributions from the following two field-enhancement mechanisms: (1)
the excitation of surface plasmon resonances and (2) the lightning-rod
effect. Here, we demonstrate the use of the SHR as a highly efficient nonlinear optical element for: (i) the generation of the third harmonic from a single SHR; (ii) the excitation of intense multiphoton luminescence from a single SHR.  Multiphoton photoluminescence from a SHR nanostructure formed in an aluminum film. (a) an electron microscope image of the nanostructure formed by a nanohole of 380 nm diameter and nanorod of 220 nm (length) × 120 nm (width), (b) calculated enhancement of the electric field amplitude inside the SHR of Fig. 7(a) upon irradiation of the nanostructure by a plane monochromatic wave with a wavelength of 1560 nm, (c) an optical image of the nanostructure upon its laser irradiation at a wavelength of 1560 nm and detection in the spectral range 400–800 nm, and (d) measured emission spectrum of multiphoton luminescence. |
Subwavelength light localization based on optical nonlinearity and light polarization
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We propose
and experimentally realize subwavelength light localization based on
the optical nonlinearity of a single nonlinear element in
nanoplasmonics—a split hole
resonator (SHR). The SHR is composed of two basic elements of
nanoplasmonics, a nanohole, and a nanorod. A peak field
intensity occurs at the single spot of the SHR nanostructure. We
demonstrate the use of the SHR as a highly
efficient nonlinear optical element for (i) the construction of a
polarization-ultrasensitive nanoelement and,
as a practical application, (ii) the building up of an all-optical
display. References: |
 Calculated 2D spatial temperature distribution and its one-dimensional cross-section in the following nanostructures exposed to laser radiation with an intensity 8×1013 W cm-2(a) aluminum nanorod of size 50 nm × 50 × nm × 570 nm; (b) nanoslit of size 50 nm × 570 nm in a 50 nm thick aluminum film. |
A
greater gain in the efficiency of the THG from the nanoslit can be
realized by increasing the exciting laser light, since the THG signal
depends on the intensity to the third power. However, this approach is
limited by destruction of the nanostructure under intense radiation.
The change in the geometry of gold nanorods under intense femtosecond
laser radiation was studied and it was found that the nanostructure
geometry did not change up to intensities 1010 W cm2. At higher
intensities the metal begins to melt, which causes the nanorod shape
and, hence, its resonant properties to change as well. According to the
Babinet principle for PEC nanostructures, light scattering on a nanorod
is identical to nanoslit transmission (with the appropriate
substitution of radiation polarization). However, the thermal behavior
of nanostructures and nano-openings at high laser intensities differ
significantly. Below we show that the effective heat withdrawal in a
film makes it possible to use much higher laser powers with nanoslits
than with nanorods when the sample is not melted yet. Measured profiles of a two-dimensional optical images of a nanoslit formed by THG radiation from the nanoslit (blue curve) and by THG radiation from a 50 nm thick Al film without a nanoslit (black curve). The inset shows a nanoslit image in an electron microscope. References:
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Institute for spectroscopy RAS, Fizicheskaya Str., 5, Troitsk, Moscow, 142190 Russia
phone: +7 495 851-02-33
e-mail: atom.nano.optics@gmail.com