排序方式: 共有25条查询结果,搜索用时 15 毫秒
1.
We investigate linear and nonlinear effects induced by the scattering of femtosecond optical pulses by cavity-shaped two-dimensional
distributions of metallic cylinders. In particular, by employing a numerical method based on the multiple scattering matrix
algorithm, we demonstrate that, at both the fundamental frequency and the second harmonic, such arrays of metallic nanowires
support localized (cavity) surface plasmon–polariton modes with characteristic lifetime ranging from a few tens of femtoseconds
to more than a hundred of femtoseconds. 相似文献
2.
Duygu İNCİ 《应用有机金属化学》2020,34(12):e6016
NOO-type tridentate Schiff base, N-salicylidene-2-aminobenzoic acid, (H2L), and its ternary Cu (II) complex containing H2L Schiff base and 4,7-dimethyl-1,10-phenanthroline (4,7-dmphen), [Cu(4,7-dmphen)(H2L)]27H2O, have been synthesized and characterized by CHN analysis, ESI-MS, FTIR, and single-crystal X-ray diffraction techniques. The interaction of alone H2L Schiff base ligand and ternary Cu (II) complex with biomacramolecules {calf thymus DNA (CT-DNA) and bovine serum albumin (BSA)} has been investigated by electronic absorption and fluorescence spectroscopy. The experimental results indicate that H2L Schiff base ligand and ternary Cu (II) complex bind to CT-DNA by means of a moderate intercalation mode. Furthermore, the fluorescence quenching mechanism between H2L Schiff base ligand and ternary Cu (II) complex with BSA possesses a static quenching process. Radical scavenging activity of H2L Schiff base ligand and ternary Cu (II) complex was measured in terms of EC50, using the DPPH and H2O2 methods. Biomacromolecule interactions and scavenging activity studies revealed that ternary Cu (II) complex yielded better results than H2L Schiff base ligand alone. 相似文献
3.
We demonstrate that strong modulation instability (MI) of copropagating optical waves can be observed in Si photonic nanowires with a length of only a few millimeters. We consider two distinct cases, namely one in which one wave propagates in the normal group-velocity dispersion (GVD) region and the other one experiences anomalous GVD, and a second case in which both waves propagate in the anomalous GVD region. In both cases we show that, for comparable optical powers, the peak value of the MI gain spectrum is 2 to 3 orders of magnitude larger than that achieved in optical fibers. 相似文献
4.
We demonstrate chip-scale flat-top filters at near-IR wavelengths using negative index photonic crystal based Mach-Zehnder interferometers. Supported by full three-dimensional numerical simulations, we experimentally demonstrate a new approach for engineering high-pass, low-pass, bandpass, and band-reject filters, based on designing the photonic band diagram both within the bandgap frequency region and away from it. We further show that our approach can be used to design filters that have tunable multilevel response for different sections of the spectrum and for different polarizations. This configuration enables deterministic control of the bandwidth and the rejection ratio of filters for integrated photonic circuits. 相似文献
5.
6.
7.
An approach based on the finite-difference time-domain method is developed for simulating the dynamics of passive mode locking in vertical-cavity surface-emitting lasers (VCSELs). The material response is modeled by the effective semiconductor Bloch equations through a resonant polarization term in the Maxwell's equations. Nonlinear gain saturation is incorporated through a gain compression factor in the equation governing the dynamics of the resonant polarization. An extended-cavity VCSEL with a quantum-well saturable absorber is simulated, and stable mode-locking pulses are obtained. Fine features of the spatial profile of the mode-locked pulses are also studied within this approach. 相似文献
8.
We demonstrate that an array of discrete waveguides on a slab substrate, both featuring chi2 nonlinearity, supports stable solitons composed of discrete and continuous components. Two classes of fundamental composite soliton are identified: ones consisting of a discrete fundamental-frequency (FF) component in the waveguide array, coupled to a continuous second-harmonic (SH) component in the slab waveguide, and solitons with an inverted FF/SH structure. Twisted bound states of the fundamental solitons are found, too. In contrast with the usual systems, the intersite-centered fundamental solitons and bound states with the twisted continuous components are stable over almost the entire domain of their existence. 相似文献
9.
10.
Metal-based negative refractive-index materials have been extensively studied in the microwave region. However, negative-index metamaterials have not been realized at near-IR or visible frequencies due to difficulties of fabrication and to the generally poor optical properties of metals at these wavelengths. In this Letter, we report the first fabrication and experimental verification of a transversely structured metal-dielectric-metal multilayer exhibiting a negative refractive index around 2 microm. Both the amplitude and the phase of the transmission and reflection were measured experimentally, and are in good agreement with a rigorous coupled wave analysis. 相似文献