We demonstrate a convenient method to improve the surface Plasmon resonance sensitivity by manipulating the
permittivity of active medium using metal-dielectric (Ag-SiO2) composite monolayer. We demonstrate the successful
permittivity engineering of SPR active medium in both theory and experiments. Based on the basic theory of SPR and
Bruggeman effective medium theory (EMT), we theoretically confirm that the angular sensitivity enhances using
manipulated permittivity of metal-dielectric composite layer.
Recently, the near-field superlens (NFSL) has been used as a suitable material for the super-resolution beyond the
diffraction limits. These NFSL materials in the nature, such as metals and polar dielectric crystals, usually have intrinsic
absorption loss in the Re(ε) < 0 region. In the imaging system, such absorption loss decreases the retardation effects by
softening the singularity of transmission resonances, but it does not remove the phase singularity that severely
deteriorates the ideal image restoration. Because of this problem, TiO2 thin film cannot still have sufficient band of
spatial frequency for the super-resolution in the mid IR regime. In this research, we report the achievement super-resolution
in TiO2 NFSL by elimination of the phase singularity based on the phase correction method.
We design the THz lens made of slit-groove-based metamaterials with tunable far-field focal length as well as
subwavelength resolution, based on surface plasmons(SP) diffraction theory into spoof SP of THz region. In THz
regime, the curved depth profile of grooves from both sides of metal slit produce directional beaming and mimic SP at
the same time. By arranging the depth of grooves in traced profile, it is possible to optimize the focal position in THz
region without changing the size of structure. It is performed numerical simulation of a designed structure through finite-difference
time-domain (FDTD) method and shows the subwavelength imaging of the designed position. In addition, the
change of focal length and the relative Ex phase are observed in the simulation and help to comprehend a subwavelength
1D slit-groove-based metamaterials in THz regime.
In the manufacturing process of stainless steel, it is essential to pickle the oxide layer of steel surface for high corrosion
resistance and fine surface quality. Pickling liquor of stainless steel is commonly composed of mixed hydrofluoric and
nitric acid. Real time monitoring of concentrations of each acid is crucial to optimize pickling process. It also reduces
cost of production and decreases the generation of waste acid. We used non-contact near infrared spectroscopy
technique and rapid analysis method, for the quantification of each acid in an on-line manner. Multivariate calibration
such as partial least square regression method is employed for the better prediction results.
Recently, the near-field superlens (NFSL) based on the negative permittivity (ε < 0) has been much attraction issue
because of its useful application in a near-field imaging system beyond the diffraction limits. Silver in the UV region and
silicon carbide in the mid-IR regime has been reported as suitable materials for the NFSL. However, these materials have
the intrinsic absorption loss, which blurs the near-field image. In this research, we theoretically predict enhancement of
image quality in a lossy NFSL system using the full-wave numerical approach and electrostatic approximation method.
As a result, we recognized that an unmatched NFSL has better image quality compared to the traditional match NFSL.
Ag slab near-field superlens (NFSL) has been much attractive issue due to their application of nano-imaging by the
resolution beyond the diffraction limits. Although it has the advantages as sub-wavelength imaging tools, Ag NFSL
always suffers from image blurring due to the intrinsic absorption loss, which prevent the ideal reconstruction of nanoimaging.
In this research, through the analysis of focal property using the FDTD, we recognized that the impedance
mismatched Ag NFSL is useful as the phase corrected optical components in the near-field. As a result, the significant
enhanced of visibility, depth of field, and resolving capability is achieved in the mismatched Ag NFSL imaging system.
In the optical lithography technique, the higher aspect ratio is critical as well as small spot size. To achieve higher
aspect ratio with the same nano scale spot size, in this report, we control the confocal parameters of Ag superlens by
changing the position of lens. In our FDTD (Finite Difference Time Domain) calculation, Drude dispersion is
employed to represent the frequency-dependent permittivity of the Ag superlens while the refractive index of Ag
matches with the host material, air and PMMA, at the wavelength of 338nm and 360nm. By changing the wavelength
from 330nm to 340nm, in addition, we investigated the tunable superlensing effects and the amplification of evanescent
wave with Ag slab related to surface plasmon polariton. Consequently, we observed the variation of the confocal
parameters of Ag superlens depending on the position and the tunable wavelength in our results.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.