排序方式: 共有24条查询结果,搜索用时 15 毫秒
1.
N.M. Litchinitser M. Sumetsky P.S. Westbrook 《Journal of Optical and Fiber Communications Reports》2007,4(1):41-85
Tunable dispersion has been implemented in various technology platforms, including fiber gratings, planar waveguides, thin
film etalons, and bulk optic technologies. This paper will focus on fiber grating based tunable dispersion compensation, because
fiber gratings are at present one of the best developed TDC technologies available. The paper is divided into three parts.
In the first part we describe grating based TDC technologies and discuss their advantages and disadvantages. We focus on thermally
tuned linearly chirped fiber gratings, as these have to date been the most successful grating technology for 40 Gbit/s. We
also compare grating TDCs to two other prominent tunable dispersion technologies: thin film etalons and planar waveguide ring
resonators. In the second section we describe the techniques used to fabricate high performance dispersion compensation gratings
as well as the theory of the primary defect of fiber grating dispersion compensation: group delay ripple (GDR). In the third
section we describe the telecom system related issues for tunable gratings, including characterization of grating performance,
tunability requirements and results from actual system trials using tunable FBGs. 相似文献
2.
Resonance and scattering in microstructured optical fibers 总被引:2,自引:0,他引:2
White TP McPhedran RC Martijnde Sterke C Litchinitser NM Eggleton BJ 《Optics letters》2002,27(22):1977-1979
We present an investigation into the mechanism for guidance of microstructured optical fibers consisting of high-refractive-index cylinders embedded in a low-index background. A new guidance regime is identified in which the fibers' confinement losses depend strongly on wavelength and the positions of the loss minima and maxima depend on the scattering properties of individual cylinders and only weakly on their position and number. We point out similarities between these results and those reported recently for two-dimensional antiresonant reflecting waveguides. 相似文献
3.
John W.Grove 《数学物理学报(B辑英文版)》2010,30(2):563-594
This article describes mathematical models for phase separated mixtures of materials that are in pressure and velocity equilibrium but not necessarily temperature equilibrium. General conditions for constitutive models for such mixtures that exhibit a single mixture sound speed are discussed and specific examples are described. 相似文献
4.
The propagation of pulses in the system of two tunnel-coupled optical waveguides from optically nonlinear materials one of which has a negative refractive index, while the other one, positive, is investigated theoretically. The propagation of nonlinear waves in this structure is studied based on the model of coupled modes. For linear waves, this pair of coupled waveguides behaves as a mirror resulting in the change of direction of the energy flow upon penetration of radiation from one waveguide to the other. The solutions to the system of nonlinear equations describing the stationary propagation of the solitary wave, the gap soliton, in a particular direction are found. This soliton is formed by the coupled pair of wave packets each localized in the corresponding waveguide. 相似文献
5.
Resonant enhancement of electromagnetic waves propagating at oblique incidence in metamaterials, with dielectric permittivity and magnetic permeability linearly changing from positive to negative values, has been predicted and theoretically studied. This effect occurs for both TE and TM polarizations near the point where a refractive index changes its sign. Our model elucidates the unique features of the resonant enhancement in "positive-to-negative transition" metamaterials for a broad frequency range from microwaves to optics. 相似文献
6.
A novel refractometric sensor utilizing unique spectral properties of antiresonant-guiding microstructured optical fibers is proposed. The sensor operation is based on the wavelength shift of the transmission spectrum in response to the refractive index change of a sample loaded in the air-holes of the microstructured optical fiber. Refractive index changes on the order of 0.1% can be detected using less than a nanoliter of a sample. 相似文献
7.
R. Biswas J. Zeng M. Kandel A. T. Fam A. N. Cartwright N. M. Litchinitser 《Applied physics. B, Lasers and optics》2011,105(2):329-333
We propose, design, and experimentally demonstrate a novel, simple, distributed refractometric measurement technique based
on unique spectral properties of antiresonant-guiding photonic crystal fibers for measuring temperature gradients. We use
a simple and accurate analytical model and numerical simulations to guide our experiments. The proposed technique may find
applications for monitoring and control of chemical and biological reactions in microfluidic systems. 相似文献
8.
Nonlinear optical pulse compression of picosecond pulses typically requires long lengths of optical fiber and multiple components. Periodic structures, such as fiber Bragg gratings, are highly dispersive at wavelengths outside of the photonic bandgap. This implies that such gratings can be used as very short all-fiber compressors. In this paper a number of such compression schemes are reviewed involving uniform and nonuniform fiber Bragg gratings, relying on both soliton and nonsoliton compression principles. Experimental results supporting the corresponding underlying theory are also presented. Finally, an extension of one of the compression schemes is shown, which allows the generation of adjustable high-repetition rate soliton trains. 相似文献
9.
OG Khvostenko ZS Yarullina NM Shishlov VE Rusin 《Rapid communications in mass spectrometry : RCM》1999,13(12):1091-1097
A correlation between the energies of electronic singlet transitions in benzodiazepines and their biological activity, which was revealed earlier by means of negative ion mass spectrometry with resonance electron capture, has been verified with a UV absorption spectroscopy investigation. Also, it has been noted that the energies of electronic singlet transitions in benzodiazepines are close in value to the ionization energies of atoms Cs, Rb, K, Na, Li and Tl, the cations of which are known to play an important role in nerve cell excitation processes. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
10.
AM Cardoso SM Alexandre CM Barros AJ Correia NM Nibbering 《Rapid communications in mass spectrometry : RCM》1999,13(19):1885-1888
The collision-induced dissociation (CID) of deprotonated arylalkylamines of general formula R(1)C(6)H(4)CHR(2)CH(2)NR(3)(2) (where R(1) = H, OH, F or NO(2); R(2) = H or OH; R(3) = H or CH(3)) generated by negative chemical ionization with H(2)O and D(2)O as ionizing reagents, is discussed. The negative chemical ionization mass spectra show that, in the absence of a hydroxy group in the aromatic ring, deprotonation takes place at the benzylic position whereas the proton is lost from the OH group when present. The nitro compound forms only M(-.) ions. The CID spectra of the deprotonated molecules show that fragmentations are strongly dependent on the structural features of the molecules, namely the presence or absence of substituents in the aromatic ring or aliphatic chain. Copyright 1999 John Wiley & Sons, Ltd. 相似文献