共查询到20条相似文献,搜索用时 109 毫秒
1.
We investigate the potential of plasmonic resonance in metal nanocomposite materials for the design of photonic crystal all optical switches by numerical methods. We study the absorption effect of the plasmonic resonance on the Fano resonances of one dimensional photonic crystal slabs covered by a metal nanocomposite layer. It is shown that the absorption reduces the contrast of the Fano resonances. However, for adequate metal nanoparticle concentrations it is possible to achieve both sufficiently sharp Fano resonance and strong Kerr nonlinearity, which provides a suitable condition for the design of high contrast and low threshold switches. 相似文献
2.
Markov A Reinhardt C Ung B Evlyukhin AB Cheng W Chichkov BN Skorobogatiy M 《Optics letters》2011,36(13):2468-2470
A type of a plasmonic waveguide has been proposed featuring an "open" design that is easy to manufacture, simple to excite and offers convenient access to a plasmonic mode. Optical properties of photonic bandgap (PBG) plasmonic waveguides are investigated experimentally by leakage radiation microscopy and numerically using the finite element method confirming photonic bandgap guidance in a broad spectral range. Propagation and localization characteristics of a PBG plasmonic waveguide have been discussed as a function of the wavelength of operation, waveguide core size, and the number of ridges in the periodic reflector for fundamental and higher order plasmonic modes of the waveguide. 相似文献
3.
《Laser \u0026amp; Photonics Reviews》2017,11(6)
Owing to exotic optical responses, metallic nanoparticles and nanostructures are finding broad applications in laser science, leading to numerous design variations of plasmonic nanolasers. Nowadays, two of the most intriguing plasmonic nanolasing devices are spasers and random lasers. While a spaser is based on a single metallic nanoparticle resonator with the optical feedback provided by the localized surface plasmon resonance, the operation of a random laser relies on multiple light scattering within randomly distributed metallic nanoparticles. In this paper, an up‐to‐date review on the applications of metallic nanoparticles in spasers and random lasers is provided. Principles of a random spaser, a device combining the features of a spaser and a random laser, are briefly discussed as well. The paper is focused on major theoretical and experimental approaches to control the core metrics of lasing performance, including threshold, resonant wavelength, and emission directionality. The applications of spasers and random lasers in the fields of sensing and imaging are also mentioned. Finally, the challenges and future perspectives in this area of research are discussed. 相似文献
4.
Ivan S. Maksymov 《Physics letters. A》2011,375(5):918-921
We propose a hybrid resonance architecture in which a plasmonic element is coupled to a silicon-on-insulator photonic crystal nanobeam cavity operating at telecom wavelengths. It benefits from the combined characteristics of the photonic cavity and the plasmonic element, and exploits the unique properties of Fano resonances resulting from interactions between the continuum and the localized cavity states. As confirmed through 3D time-domain simulations, a strong cavity mode damping by the plasmonic element offers mechanisms of controlling a probe signal propagating in the nanobeam. It makes possible to create optical switching devices and logic gates relying on any optical nonlinear effect. 相似文献
5.
We experimentally demonstrate a metal-film bidirectional surface wave splitter for guiding light at two visible wavelengths in opposite directions. Two nanoscale gratings were patterned on opposite sides of a subwavelength slit. The metallic surface grating structures were tailored geometrically to have different plasmonic bandgaps, enabling each grating to guide light of one wavelength and prohibit propagation at the other wavelength. The locations of the bandgaps were experimentally confirmed by interferometric measurements. Based on these design principles, a green-red bidirectional surface wave splitter is demonstrated, and the observed optical properties are shown to agree with theoretical predictions. 相似文献
6.
We investigated the plasmonic resonance enhanced two-photon photopolymerization (PETPP) using the isolated chemical synthesized
gold nanorods for fabrication of polymer/metal nanocomposites. The isolated gold nanorods with the plasmonic resonance band
around 750 nm covered by photoresist were irradiated by a femtosecond laser with the wavelength of 780 nm. The PETPP trigged
by the plasmonic resonance enhancement of gold nanorods was localized only in the distance smaller than 30 nm from the surface
of gold nanorods, which matched the distance of plasmonic resonant enhanced field of the gold nanorod. The shapes of obtained
polymer/gold nanocomposites were changed from the “dumbbell” to the “ellipsoid” with the increase of laser irradiating intensity
used for PETPP. This study would provide a potential method for fabricating the plasmonic nanomaterials and nanostructures
of polymer/metal nanocomposites, which could be expected to be applied in the emerging fields such as nanophotonics, nanobiosensor,
nanolithography. 相似文献
7.
Junbo Lou Shuguang Li Tonglei Cheng Xin Yan Xuenan Zhang Yaonan Shao 《Optical and Quantum Electronics》2017,49(12):415
A novel polarization filter based on plasmonic photonic crystal fiber with Au-coated and liquid-filled air holes is presented in this paper. The coupling theory is introduced to explain the complete coupling and incomplete coupling. We can adjust the resonance point to the communication band by optimizing the parameters of the fiber structure. Numerical simulation results demonstrate that the resonance strength can reach 489.78 dB cm\(^{-1}\) at the communication wavelength of 1.55 um in x-polarized direction. By filling liquid analyte the confinement loss can reach 572.55 dB cm\(^{-1}\) at the wavelength of 1.55 um. When the fiber length of L equals to 800 um, the peak value of the crosstalk can reach 394.75 dB at the wavelength of 1.55 um, and the bandwidth of the crosstalk better than 20 dB is up to 180 nm when the length of the fiber L is 200 um. These features make it a promising candidate for designing new types of polarization filter devices. 相似文献
8.
We investigated the role of nanoparticle surface morphology (facets) in estimating the plasmonic properties of nanoparticle-on-a-mirror design or NPOM in the presence of a thicker (20 nm) dielectric layer. Nanoparticle surface morphology differences ranging from smoother surface to multi-facets in the form of a sphere (NSOM), cube (NCOM), and singe bottom faceted sphere (SBF-NSOM) shapes have been employed. Three significant optical properties were observed. Better longer wavelength near-field and far-field resonance spectral positions from NCOM are achieved. Near-field enhancement extracted from SBF-NSOM outperformed NCOM by more than ∼ two times. Plasmonic gap mode enhancement is absent for NSOM in the presence of a larger dielectric layer. The availability of plasmonic gap modes in NCOM and SBF-NSOM, even at a 20 nm thick dielectric layer, is highly beneficial for various plasmonic applications. These differences in optical properties are understood by the role of NP facets in influencing the plasmonic cavity region. 相似文献
9.
介电常数为零或近零模式在微纳结构中提供了一个新的方式调控光与物质的相互作用.本文首先利用金属圆盘阵列结构激发了表面等离激元共振,在共振频率处实现了光的局域效果;然后通过在金属-绝缘体-金属超表面微纳结构中加入掺杂半导体材料,利用上层金属圆盘阵列激发的表面等离激元共振诱导介电常数近零模式的产生,从而使得介电常数近零模式与表面等离激元模式发生耦合,在中红外波段实现了一个470 nm的宽带吸收效果;数值模拟结果显示,在宽带吸收处存在光场的强局域效果.与窄带吸收相比,宽带吸收有更广泛的应用,比如吸收器、传感器、滤波器、微测辐射热计、光电探测器、相干热发射器、太阳能电池、指纹识别和能量收集装置等. 相似文献
10.
11.
In this paper, two kinds of modified surface plasmonic
waveguides formed by nanometric parallel lines are proposed. The
finite-difference frequency-domain method is used to study
propagation properties of the fundamental mode supported by these
surface plasmonic waveguide structures. Results show that the
transverse magnetic field of the fundamental mode is mainly
distributed in the face to face region formed by two rods. With the
same geometrical parameters and the same working wavelength of
632.8~nm, in the case of rods with a triangular cross-section, the
degree of localization of field is strong, i.e. the mode area is
small, but the fraction of the modal power in the metal increases,
so the effective index increases and the propagation length of the
mode decreases. With the same geometrical parameters, relative to
the case of a working wavelength of 632.8~nm, when working wavelength
is large, the mode area of transverse magnetic field distribution is
large, i.e. the degree of localization of field is weak, and the
interaction of field and silver is weak too, then the effective
index decreases, so the propagation length increases. The rounded
radii of rods have a great influence on the performance of the surface
plasmonic waveguides with rounded triangular cross-sections, but have
little influence on the performance of surface plasmonic waveguides
with rounded square cross-sections. Since the distribution of
transverse magnetic field, effective index, propagation length and
the mode area can be adjusted by the geometrical parameters, this
kind of modified surface plasmonic waveguide can be applied to the
field of photonic device integration and sensors. 相似文献
12.
Vladimir V. Lebedev Sergey S. Vergeles Petr E. Vorobev 《Applied physics. B, Lasers and optics》2013,111(4):577-588
We theoretically examine plasmonic resonance excited between two close metallic grains embedded into a dielectric matrix. The grains sizes are assumed to be much less than the wavelength of the electromagnetic wave in the dielectric medium and the grain’s separation is assumed to be much smaller than the grains sizes. A qualitative scheme is developed that enables one to estimate frequency of the plasmonic resonance and value of the field enhancement inside the gap. Our general arguments are confirmed by rigorous analytic solution of the problem for simplest geometry—two identical spherical grains. 相似文献
13.
We report on the theoretical concept of the design of a compact plasmonic tunable filter made of a metal–dielectric–metal waveguide and using elasto-optic effects. The proposed device is designed in a nanoring resonator structure and numerically studied by means of 3D-FEM simulations. We obtained an optimized nanoring resonator that has a radius R=390 nm and resonances at the telecommunication wavelength of 1.58 μm. Simulations using elasto-optic material as the dielectric layer and top and bottom Ag layers as electrodes indicate that the output can be tuned in the telecommunication wavelength range with an applied field. Further, using the proposed device, optical switching phenomenon is also found to be possible. This tunable ring resonator filter with ultra-small radii is considered valuable for photonic integrated systems. 相似文献
14.
15.
Tingting Tang 《Optik》2013,124(24):6757-6759
We study the optical modes in a plasmonic waveguide with electrically anisotropic metamaterial and dielectric, including symmetric (anti-symmetric) photonic mode and symmetric (anti-symmetric) plasmonic mode. The dispersion curves for these modes are derived, and a graphical method is used to calculate the solution of symmetric photonic mode and anti-symmetric plasmonic mode. By simulation results the conditions of the existence for these modes are deduced in each case. 相似文献
16.
A compact wavelength demultiplexing structure based on arrayed metal-insulator-metal (MIM) slot cavities is proposed and demonstrated numerically. The structure consists of a bus waveguide perpendicularly coupled with a series of slot cavities, each of which captures SPPs at the resonance frequency from the bus waveguide and tunes the transmission wavelength by changing its geometrical parameters. A cavity theory model is used to design the operating wavelengths of the structure. Moreover, single band transmission of each channel and the adjustable transmission bandwidth can be obtained by altering the drop waveguide positions and the coupling distance. The proposed arrayed slot cavity-based structure could be utilized to develop ultracompact optical wavelength demultiplexing device for large-scale photonic integration. 相似文献
17.
贵金属纳米材料在入射光激发下能够产生表面等离激元,即金属表面自由电子产生集体振荡。当其振荡频率与入射光频率相同时,发生表面等离激元共振,形成一种特殊的电磁场模式和光谱特性。利用该电磁场模式和光谱特性, 能够调节金属纳米材料的光谱学行为,例如通过改变金属纳米结构的大小、形状以及周围介质介电常数等参数, 在微纳尺度上实现光谱学信号的有效调控。目前,除了具有一定对称性的贵金属纳米材料被大量研究和应用外,非对称纳米结构的表面等离激元光谱特性也受到广泛关注。研究表明,在可见-近红外波段光谱范围内设计表面等离激元光电传感器件的关键问题在于,如何有效地调节其消光谱的共振波长、半峰宽以及峰值强度等主要特征参数。提出一种基于银纳米双环组成的非对称结构,利用时域有限差分方法,在可见-近红外波段内,通过分别改变银纳米双环的尺寸、间距及入射光偏振方向等参数,计算了该纳米结构在不同条件下的消光谱。结果表明,在0.4~3 μm的消光谱内,入射光能够激发产生两个独立的表面等离激元共振峰。通过研究峰值波长处的电场分布图发现,上述共振峰分别对应两种不同的电磁场模式。结果还表明,消光谱内两个独立的共振峰可以通过改变该双环结构的不同参数,被分别地进行调节。其中,可以通过改变该双环结构的半径来有效调节短波长峰的共振波长和半峰宽,同时保持长波长峰的共振波长和半峰宽基本不变。此外,通过改变两环间距或入射光偏振方向,可以分别以不同趋势来调节两个共振峰的峰值强度。在提出的非对称银纳米双环的消光谱中,获得了能够被分别调节的两个表面等离激元共振峰,研究结果能够为可见-近红外波段内基于银纳米材料光电传感器件的开发设计提供理论基础。 相似文献
18.
Two-dimensional metallic photonic crystals with different filling factors were manufactured and investigated by broadband terahertz spectroscopy. This technique allowed an independent determination of conductivity and dielectric permittivity in an extremely large dynamic range. Nearly ideal plasmonic behavior is observed for all compositions. Transmittance maxima are observed close to the plasma frequency and attributed to the longitudinal resonance. The plasmon frequencies agree well with existing calculations, while damping effects are underestimated by almost 1 order of magnitude. 相似文献
19.
We demonstrate adiabatic wavelength shifting by electro-optic modulation, using a p-i-n integrated high-Q photonic crystal nanocavity. The wavelength of the trapped light is adiabatically shifted by modulating the resonance of the cavity faster than the photon lifetime. The cavity resonance is changed by injecting electrons through a p-i-n junction to reduce the refractive index. In addition, we employ adiabatic wavelength shifting in a demonstration of dynamic Q tuning by electro-optic modulation. 相似文献
20.
《Photonics and Nanostructures》2009,7(4):212-219
Patterning of deeply subwavelength artificial nanomaterials, e.g. photonic crystals or plasmonic metamaterials, for the visible or near-infrared optical spectrum is a challenging task. Electron-beam lithography is often the method of choice thanks to its combination of flexibility, accuracy and availability in many research laboratories. In this article an analytical model for large and dense arrays of photonic nanostructures is presented which allows to predict the maximum fill ratio (radius divided by nearest neighbor distance) before the onset of resist loss between the individual elements. The model includes geometrical parameters of the design (lattice constant, lattice symmetry), the resist contrast and proximity parameters (beam broadening, backscatter range, backscatter efficiency). It is shown that the resist contrast has a significant impact on the achievable maximum fill ratio even for large nearest neighbor distances and that the beam broadening is of paramount importance. The background energy level which is determined by the backscatter efficiency and the lattice symmetry is shown to have a weaker influence on the maximum fill ratio. The derived model can be used as a guideline in the project planning stage to predict achievable fill ratios at a planned lattice constant and consequently an assessment whether a desired functionality at a certain wavelength is possible or not. 相似文献