This Letter reports on the assembly on the tip of an optical fibre of a metamaterial film fabricated by a self‐assembly bottom‐up method, composed of silver nanowires embedded in an alumina matrix. By illuminating the film through the fibre in a reflection configuration, we observe experimentally the optical response of the metamaterial in agreement with theoretical predictions and interpreted as the excitation of surface plasmon‐polaritons in the cylindrical surface of the nanowires. These results pave the way for low‐cost optical fibre devices that incorporate metamaterial films.
Results of study of nonlinear processes occurring during the propagation of light pulses in optical fibers doped with atoms of rare-earth elements under conditions of atomic coherence and interference are presented. For a three-level Λ scheme of interaction, the linear (χ(1)) and nonlinear (χ(3)) susceptibilities of such a medium are calculated. It is shown that the coefficients of Kerr nonlinearity and nonlinear absorption can reach extremely large values and can be negative. The competition between linear and nonlinear processes in the Λ scheme allows one to obtain compensation regimes when the coefficients of dispersion or absorption of the optical fiber material vanish. The efficient control of the optical properties of such a system over wide limits proves to be possible owing to variations in the parameters of light pulses at the input of the medium. The necessary conditions for realizing regimes with “slow” light, as well as for self-compression of a probing pulse on ultimately small spatial scales in a doped optical fiber, were obtained. 相似文献
An inline measuring method of the optical absorption coefficient for liquid based on optical microfiber (OM) is studied. If an OM is immersed into absorptive liquid, the additional loss of the OM will increase. We have analyzed the relationship between the additional loss of the OMs and the absorption coefficients of the liquids, and found that the OM with determinate construction will be useful for measuring the absorption coefficients of the liquid whose refractive index is lower than that of the OM. Two OM samples are prepared to measure the absorption coefficient of pure water. A supercontinuum source is launched into the OM sample which is immersed into pure water, and absorption spectrum from 1400 to 1700 nm has been achieved by monitoring the additional loss. The trend of the absorption spectrum is similar with that of the reported result, showing that the inline measurement of the optical absorption coefficient is a feasible method for those lower refractive index liquids. 相似文献
Recent theoretical works on the physics of the fiber fuse effect in optical fiber are reviewed. A qualitative interpretation of the significant increase in the absorption of quartz glass with increasing temperature is presented. The results of the 2D simulation of the optical discharge propagation in optical fiber are analyzed. The results of the simulation are in agreement with the recent measurements of the spatial distribution of the bright-spot radiation intensity. It is demonstrated that the recently demonstrated fast propagation of the optical discharge can be interpreted as light detonation. A mechanism for the formation of a chain of cavities in the fiber-fuse track is considered. It is demonstrated that this effect cannot be interpreted using the Rayleigh capillary instability due to the relatively high viscosity of glass. The periodicity of the cavities can be related to an instability of a new type. A high-density double layer of charges emerges at the plasma-liquid interface. A tendency towards an increase in the surface owing to the repulsion of like charges provides for a development of the instability that causes the formation of the chain of cavities. 相似文献
Possible applications of polymer materials in optical systems and devices are defined mainly by their optical properties in terms of refractive indices, transmission, dispersion and thermo-optic coefficients. We have examined more than twenty types of optical plastics including basic, commercial and some new development materials. Detailed measured refractometric data and transmission spectra in the visible and near infrared regions are presented. Variation of refractive indices with temperature is considered to obtain the thermo-optic coefficients. Discussion on dispersion of studied optical polymers and comparison to glass is included on the base of a number of dispersive characteristics and curves. 相似文献
2D simulation of the optical discharge propagation in an optical fiber is performed. In contrast to the previous works, the temperature dependences of the transfer coefficient are taken into account for the bright-spot plasma. The results are compared with the recently published measurements of the spatial distribution of the bright-spot radiation intensity. Good agreement is obtained for the discharge propagation velocity and the dependence of the bright-spot size on the laser power. 相似文献
Multiple-beam Fizeau fringes technique with an opto-thermal device is used to study the effect of temperature on the optical properties of Philips graded-index optical fibres. The refractive index profile of the optical fibre is measured at different temperatures. From these profiles the opto-thermal coefficient, the profile shape parameter α, the cladding/core maximum refractive index difference Δn and some guidance parameters of the optical fibre that play an important role in communication are determined. The variation of oscillation and dispersion energies along the diameter of the optical fibre (energy profile) are calculated at different temperatures. An empirical formula of the energy profile is obtained. Microinterferograms are given for illustrations. 相似文献
We experimentally demonstrate control of a holding-beam-enabled optical flip-flop by means of optical signals that act in a remote fashion. These optical-control signals vary the holding-beam power by means of cross-gain modulation within a remotely located semiconductor optical amplifier (SOA). The power-modulated holding beam then travels through a resonant-type SOA, where flip-flop action occurs as the holding-beam power falls above and below the switching thresholds of the bistable hysteresis. Control is demonstrated using submilliwatt pulses whose wavelengths are not restricted to the vicinity of the holding beam. Benefits of remote control include the potential for controlling multiple flip-flops with a single pair of optical signals and for realizing all-optical control of any holding-beam-enabled flip-flop. 相似文献
In this work a comparison between the performances of single and multichannel systems is reported for links with optical amplifiers, considering conventional and soliton signals, Time Division Multiplexing (TDM), and Wavelength Division Multiplexing (WM) techniques. The performance evaluation is obtained by means of numerical simulations taking into account the effects of the chromatic dispersion, the Kerr nonlinearity, and the ASE noise of the optical amplifiers. Both the regimes of constant and fluctuating chromatic dispersion along the link are studied. The possibility of implementing high-capacity optical systems for a high-bandwidth European network is evaluated. 相似文献
Using a single-beam, oscillating optical tweezers, we demonstrate trapping and rotation of rod-shaped bacterial cells with respect to the optical axis. The angle of rotation, θ, is determined by the amplitude of the oscillation. It is shown that θ can be measured from the longitudinal cell intensity profiles in the corresponding phase-contrast images. The technique allows viewing the cell from different perspectives and can provide a useful tool in fluorescence microscopy for the analysis of three-dimensional subcellular structures. 相似文献
We measure the cross-phase modulation (XPM) nonlinear indices of optical materials resulting from the interaction of an ultrashort pump pulse at 800 nm with a weak ultrashort probe pulse at 400 nm through the direct measurement of the optical phase change, using frequency-resolved optical gating. The materials studied include fused silica (SiO(2)) , borosilicate glass (BK-7), beta-BBO , and KD(*)P . This method results in a XPM nonlinear index that is in agreement with calculations based on nonlinear indices from previous self-phase modulation measurements. 相似文献
In near-field optics, measurement of vertical variations of the near field is of great interest for characterizing the efficiency of resonances such as surface plasmon polaritons. The use of the signal obtained through the lock-in amplifier using a feedback on the vertical vibration of the probe is shown to enable the reconstruction of the near field without the use of the slower technique of approach curves. Therefore, a tomography of the near field is directly available. 相似文献
In this contribution we review our latest achievements of combined experimental and theoretical studies to tailor the properties of optical metamaterials(MMs) at will. We give three examples of metamaterial designs that have been realized by means of electron-beam lithography and whose spectroscopic characteristics have been comprehensively investigated. In every case, our experiments are complemented by rigorous numerical simulations. Particular emphasis is put on the significance of such tailored effectiv... 相似文献