共查询到20条相似文献,搜索用时 0 毫秒
1.
Mohamadreza Najiminaini Fartash Vasefi Bozena Kaminska Jeffrey J. L. Carson 《Plasmonics (Norwell, Mass.)》2013,8(2):217-224
We report a 3D plasmonic nanostructure having an extraordinary optical transmission due to localized surface plasmon (LSP) coupling between nanoholes and nanodisks. The nanostructure contains a free-standing gold nanohole array (NHA) film above a cavity and an array of nanodisks at the bottom of the cavity that is aligned with the NHA. For the device, the LSP-mediated resonance position was dependent on the hole and nanodisk diameter as well as the separation distance. Also, the effect of LSP coupling between each hole and corresponding nanodisk became negligible for cavities deeper than 200 nm as observed as a disappearance of the LSP resonance. The greatest LSP resonance transmission and the highest electric field intensity were observed for the structure with the shallowest cavity. In addition, the structure had high surface plasmon resonance sensitivity and may have potential for surface-enhanced Raman spectroscopy and optical trapping applications. 相似文献
2.
Extraordinary transmission through a metal film with an array of subwavelength holes (mesh) can be modeled effectively using
three-dimensional finite difference time domain (3D-FDTD) calculations. A simple 3D-FDTD model, where a plane wave of light
at perpendicular incidence with no angular spread interacts with a periodic repeating mesh, models the shape and location
of the transmission resonance peaks qualitatively but not quantitatively. The simple 3D-FDTD model gives peaks that are tall,
sharp, and red-shifted compared to experimental measurements using a benchtop Fourier transform infrared (FTIR) spectrometer.
It was discovered that the simple model does not account accurately for diffraction order scattering by the mesh or the angular
spread of the actual FTIR beam. This work describes a more sophisticated model that accounts for these factors and agrees
quantitatively with experimental FTIR results. 相似文献
3.
Optical transmission properties of periodic X-shaped plasmonic nanohole arrays in a silver film are investigated by performing the finite element method. Obvious peaks appear in the transmission spectra due to surface plasmon polaritons (SPPs) on the top surface of the silver film, to the Fabry–Ferot resonance effect of SPPs in the nanohole, and to the localized surface plasmon resonance of the nanohole. Besides the topologic shape parameters of the X-shaped nanohole, transmission properties strongly depend on incident polarization. The results of this study not only present a tunable plasmonic filter, but also aid in the understanding of the mechanisms of the extraordinary optical transmission phenomenon. 相似文献
4.
We present a new style extraordinary optical transmission (EOT) nano optical filter combined by two kinds of subwavelength holes array on a gold film. In the design, a square array of non-penetrating holes (hollow holes) inlays into another square array of penetrating holes ordered by a central arrange mode. We numerically calculated the transmission spectra of the patterned gold films by finite-difference time-domain (FDTD) method. Results show that the transmission of the filter can be manipulated by changing the depth of non-penetrating holes. The (1, 1) peak can be enhanced when the incident light normally illuminates one side of the filter with the hollow holes, yet the (1, 1) peak can be suppressed when the light illuminates the other side without hollow holes. It also depicts that the hollow hole array results in energy level splitting of (1, 0) mode propagating on the surface of the filter. What’s more, the splitting can be eliminated by modulating the depth of the hollow holes. Our study further reveals the role of suface plasmon effect in the EOT. 相似文献
5.
Xiangnan Zhang Guiqiang Liu Ying Hu Zhengqi Liu Yuanhao Chen Zhengjie Cai Xiaoshan Liu Gang Gu Guolan Fu 《Plasmonics (Norwell, Mass.)》2014,9(5):1149-1153
We propose a novel plasmonic metal structure composed of a silver film perforated with a two-dimensional square array of two-level cylindrical holes on a silica substrate. The transmission properties of this structure are theoretically calculated by the finite-difference time-domain (FDTD) method. Double-enhanced transmission peaks are achieved in the visible and infrared regions, which mainly originate from the excitation of localized surface plasmon resonances (LSPRs), the hybridization of plasmon modes, and the optical cavity mode formed in the holes. The enhanced transmission behaviors can be effectively tailored by changing the geometrical parameters and dielectric materials filled in the holes. These findings indicate that our proposed structure has potential applications in highly integrated optoelectronic devices. 相似文献
6.
Adam John Baragwanath Mark Christopher Rosamond Andrew James Gallant John Martyn Chamberlain 《Plasmonics (Norwell, Mass.)》2011,6(4):625-636
A qualitative model explaining the extraordinary optical transmission of terahertz (THz) radiation through two-dimensional
periodic arrays of subwavelength apertures is presented. Systematic terahertz time-domain spectroscopy studies have been undertaken
to investigate the combined effects of the lattice arrangement, aperture shape, area and aspect ratio on the transmission
properties of electroformed copper arrays. The extensive results presented provide a unified example of how aperture geometry
dictates SPP activity. The novel fabrication method creates exemplary peak resonances, allowing the onset of surface plasmon
polariton (SPP) decoupling to be distinguished from direct transmission. Furthermore, we provide the first evidence as to
how the temporal properties of SPPs are governed by the single-cycle THz pulse. The time-of-flight model presented can not
only be used to explain the results observed in both the presented and previously published experiments but serves as a method
to engineer specific resonances for sensor applications. 相似文献
7.
The essence of levitation technology is the countervailing of gravity. It is known that an ultrasound standing wave is capable of suspending small particles at its sound pressure nodes. The acoustic axis of the ultrasound beam in conventional studies was parallel to the gravitational force, and the levitated objects were manipulated along the fixed axis (i.e. one-dimensionally) by controlling the phases or frequencies of bolted Langevin-type transducers. In the present study, we considered extended acoustic manipulation whereby millimetre-sized particles were levitated and moved three-dimensionally by localised ultrasonic standing waves, which were generated by ultrasonic phased arrays. Our manipulation system has two original features. One is the direction of the ultrasound beam, which is arbitrary because the force acting toward its centre is also utilised. The other is the manipulation principle by which a localised standing wave is generated at an arbitrary position and moved three-dimensionally by opposed and ultrasonic phased arrays. We experimentally confirmed that expanded-polystyrene particles of 0.6 mm, 1 mm, and 2 mm in diameter could be manipulated by our proposed method. 相似文献
8.
Bayaner Arigong Jiangtao Cheng Rongguo Zhou Jun Ding Yuankun Lin Hualiang Zhang 《Plasmonics (Norwell, Mass.)》2014,9(5):1221-1227
In this paper, we report novel designs of tunable THz plasmonic devices based on liquid metals. The designed devices will be able to dynamically control and change the spectrum responses of extraordinary THz wave transmissions. Different THz device configurations are investigated, and numerical simulations have been conducted to theoretically verify the performance of the proposed structures. Moreover, an equivalent circuit model has been developed to describe the operating principle of the proposed THz devices. Good agreement has been achieved between the theoretical models and the numerical results. These new THz devices are expected to be applied in various areas of sensing, communication, and imaging. 相似文献
9.
We numerically study the extraordinary optical transmission of a plasmonic structure that combines a circular nanoantenna
and a vertical annular nanoslit etched into a gold film under radially polarized illumination. The nanoantenna collects the
incident field and localizes it in a horizontal Fabry-Pérot cavity over the gold film. The vertical nanoslit positioned at
the maximal field in the horizontal cavity couples the localized field and facilitates its transmission to the free space.
Due to the symmetry matching between the structure and the illumination polarization, surface plasmons can be excited effectively
and enhance the transmission. Through optimizing the structure parameters, the transmission efficiency can be greatly enhanced
by 225 times for a resonant annular nanoslit and 251 times for a non-resonant annular nanoslit. This axisymmetric extraordinary
optical transmission setup may be fabricated on the facet of an optical fiber for optical sensing applications. 相似文献
10.
We have studied theoretically and numerically the effect of extraordinary optical transmission of light propagating through the one-dimensional periodic arrays of infinite slits with sub-wavelength dimensions. In our study, we have concentrated on mechanisms which are responsible for this effect. Within our analysis, we have attempted to draw the attention towards the origin and reasons of earlier misinterpretations concerning the spectral position of EOT prediction and the related role of surface plasmon polaritons in manifestation of the effect. Using the sequence of suitable parameter two-dimensional spaces (in terms of structure period-filling factor; thickness-wavelength; wavelength-angle), we were able to look into subtle physical mechanisms operating in the background of this extraordinary optical transmission effect. To study these effects associated with the extraordinary optical transmission, we have applied our efficient two-dimensional numerical technique based on the rigorous coupled-wave analysis. Within the thickness-wavelength parameter space, we have been able to identify and describe three distinct interaction regions, with specific behaviour. Finally, we have proposed and discussed the supporting mechanism explaining the interaction, based on the interference of resonant and non-resonant contributions at the slit openings. 相似文献
11.
Arif E. Cetin Martin Dršata Yasa Ekşioğlu Jiří Petráček 《Plasmonics (Norwell, Mass.)》2017,12(3):655-661
We investigate the extraordinary optical transmission (EOT) properties of nanohole arrays with a rectangular lattice for label-free refractive index sensing applications. We show that the deviation within the periodicities along the two axes at the nanohole plane leads to more advantageous spectral quality of EOT signal compared to the conventional square lattice geometries. We introduce a way to further improve the sensitivity of the aperture system by carefully choosing the periodicities. We introduce nanohole arrays with a rectangular lattice supporting EOT signals with larger figure-of-merit values as well as enabling much stronger light transmission. We also model a nanohole system covered with a thin dielectric layer, mimicking biomolecules captured on the gold surface, in order to show its biosensing capability. We also show that certain deviation amounts between periodicities create spectral splitting within the EOT signal leading to larger spectral shifts in the presence of a thin dielectric film. 相似文献
12.
13.
Yanxia Cui Jun Xu Yinyue Lin Guohui Li Yuying Hao Sailing He Nicholas X. Fang 《Plasmonics (Norwell, Mass.)》2013,8(2):1087-1093
In this paper, we employ an antireflective coating which comprises inverted π-shaped metallic grooves to manipulate the behaviour of a transverse-magnetic (TM)-polarised plane wave transmitted through a periodic nanoslit array. At normal incidence, such scheme cannot only retain the optical curtain effect in the output region but also generate the extraordinary transmission of light through the nanoslits with the total transmission efficiency as high as 90 %. Besides, we show that the spatially invariant field distribution in the output region as well as the field distribution of resonant modes around the inverted π-shaped grooves can be reproduced immaculately when the system is excited by an array of point sources beneath the inverted π-shaped grooves. Furthermore, we investigate the influence of centre groove and side-corners of the inverted π-shaped grooves on suppressing the reflection of light, respectively. Based on our work, it shows promising potential in applications of enhancing the extraction efficiency as well as controlling the beaming pattern of light emitting diodes. 相似文献
14.
15.
In this paper, we present a peculiar metal-dielectric-metal (MDM) nanosandwich grating structure that can achieve extraordinary optical transmission performances at normal incidence in the ultraviolet-visible-near infrared (UV-VIS-NIR) regions. The proposed structure shows three obvious spectrum characteristics: it can obtain high transmittance up to 80 % in NUV region and efficiently blocking visible wavelengths for transverse-magnetic (TM) polarized incidence; a broadband NIR polarizer can be inspired in the wavelength range from 950 to 1400 nm; more surprisingly, these performances do not deteriorated until 30° tilting angle. Compared to other grating structures with single metal overlayer, it shows wider band-stop characteristics and higher broadband transmission transmittance and extinction ratio (ER) in the investigated wavebands. We analyze the underlying physical mechanism by using numerical simulation, which is primarily attributed to metal ultraviolet transparency, surface plasmon polariton (SPP) at metal/dielectric interface, Fabry–Perot (FP)-like cavity mode within this dielectric grating, and optical magnetic resonance especially in the dielectric interlayer of the MDM sandwiched structure. This structure is very important for developing high-performance subwavelength multifunctional integrated optical devices. 相似文献
16.
Park Jongkyoon Lee Hyunsoo Gliserin Alexander Kim Kyujung Kim Seungchul 《Plasmonics (Norwell, Mass.)》2020,15(2):489-494
Plasmonics - Nanoapertures in a metallic film exhibit extraordinary optical transmission (EOT) owing to the surface plasmon resonance. Their transmission properties are known to be dependent on the... 相似文献
17.
Roberto Marani Valeria Marrocco Marco Grande Giuseppe Morea Antonella D��Orazio Vincenzo Petruzzelli 《Plasmonics (Norwell, Mass.)》2011,6(3):469-476
In this paper, a novel plasmonic bandgap cavity inducing the enhancement of extraordinary optical transmission is presented.
Numerical simulations have been performed to model a free-standing structure made of a one-dimensional periodic arrangement
of gold strips. Two different values of the lattice constant have been properly chosen to realize a double heterostructure-like
cavity to accomplish extraordinary optical transmission assisted by the formation of a plasmonic bandgap in the adjacent regions.
Numerical results prove the capability of this optical device to efficiently transmit input light beams with far-field transmission
values close to 100% due to the excitation of surface plasmon polariton resonant modes. 相似文献
18.
Young-Seok Shon Hyung Y. Choi Michael S. Guerrero Chuhee Kwon 《Plasmonics (Norwell, Mass.)》2009,4(2):95-105
This article presents a concise review of preparation methods for transparent nanostructured films, with an emphasis on their
current applications in transmission-localized surface plasmon resonance (T-LSPR) sensing. One of the first methods used for
the fabrication of transparent nanostructured metal films is a direct vacuum evaporation of thin gold films. Self-induced
formations of small gold islands result in transparent nanostructured gold arrays. The most well-established method is a nanosphere
lithography developed by Van Duyne. Nanotriangular island arrays with controlled size and optical properties can be fabricated
by this protocol. A different nanolithography method known as focused ion beam milling is reported and used for the fabrication
of nanohole arrays. Simple assembly of solution-phase synthesized nanoparticles has also been utilized for the preparation
of nanoparticle arrays capable of T-LSPR sensing. Lastly, this article also describes a new preparation strategy, in which
self-assembly/thermolysis of nanoparticle multilayers is employed to obtain transparent nanoisland architectures on glass
substrates. 相似文献
19.
Qiaoqiang Gan Wenli Bai Suhua Jiang Yongkang Gao Wendi Li Wei Wu Filbert J. Bartoli 《Plasmonics (Norwell, Mass.)》2012,7(1):47-52
We provide both experimental and theoretical investigation on extraordinary low transmission through one-dimensional nanoslit
and two-dimensional nanohole arrays on ultra-thin metal films. Unambiguous proofs demonstrate that short-range surface plasmon
polaritons play a key role leading to this novel phenomenon, which could be useful for creating new polarization filters and
other integrated plasmonic components. 相似文献
20.
Plasmonics - We study two-dimensional (2D) hole arrays drilled into a perfect conductor slab covered with a graphene sheet. Such arrays support the extraordinary transmission of electromagnetic... 相似文献