共查询到20条相似文献,搜索用时 0 毫秒
1.
The propagation constants and the field distribution of the higher-order modes in photonic-crystal fibers have been studied.
It is shown that the standard single-mode operation condition of a fiber, in which the first higher-order mode is cut-off,
is not applicable to photonic-crystal fibers because the latter can guide higher-order eigenmodes, even when this condition
is fulfilled. 相似文献
2.
A rigorous method of integral equations has been used to calculate the dispersion characteristics, fields, and radiation patterns
of the leaky modes of photonic-crystal fibers with a shell in the form of a bounded 2D photonic crystal composed of parallel
quartz capillaries contacting each other and a core in the form of a defect of a photonic crystal with one capillary removed.
It is shown that, when thick-walled capillaries (with an air content in the shell of about 28%) are used, these fibers can
be single mode and have an overlap integral of the fundamental-mode field with the dielectric medium that is smaller by a
factor of more than two (in comparison with similar fibers formed by air channels of circular cross section). The significant
dispersion of the group velocity of the fundamental modes of fibers near the edge of the photonic crystal band gap has been
found. 相似文献
3.
S. O. Konorov A. B. Fedotov O. A. Kolevatova V. I. Beloglazov N. B. Skibina A. V. Shcherbakov A. M. Zheltikov 《JETP Letters》2002,76(6):341-345
Waveguide modes of microstructure fibers with a hollow core and a two-dimensionally periodic cladding are studied experimentally and theoretically. The spectrum of modes guided in the hollow core of these fibers displays isolated maxima, indicating that waveguiding is supported due to the high reflectivity of the fiber cladding within photonic band gaps. The main properties of the spectrum of modes guided in a hollow core of a photonic-crystal fiber and radiation intensity distribution in these modes are qualitatively explained in terms of the model of a periodic coaxial waveguide. 相似文献
4.
5.
When investigating the nonlinear transmission of fullerene-doped π-conjugate organic structures, it has been found for the first time that the broad-band light of a flashlamp has considerable impact on the optical limiting of infrared laser emission (λ=1315 nm). 相似文献
6.
提出外部光注入半导体激光器混沌相位控制方法,通过周期调制注入光的相位相移将激光器的混沌控制到多种周期状态.数值结果表明:在不同强度光注入下,(1)通过半波长周期相位相移调制控制混沌激光到周期态、双周期态、三周期态、四周期态以及多周期态等;(2)通过四分之一波长周期相位相移调制控制混沌激光到周期态和多周期态,并在高频调制控制时能够产生激光锁模现象,其锁模区域是19—21GHz;(3)波长周期相位相移调制控制也能使混沌激光控制到三周期态和多周期态等.
关键词:
混沌
控制
激光器
周期 相似文献
7.
Nonlinear optical properties of semiconductor quantum wires 总被引:1,自引:0,他引:1
V. Dneprovskii E. Zhukov V. Karavanskii V. Poborchii I. Salamatina 《Superlattices and Microstructures》1998,23(6):1217-1221
Nonlinear optical transmission at discrete frequencies (bleaching bands) has been observed in CdSe and GaAs quantum wires crystallized in chrysotile asbestos nanotubes with average diameter ≈ 6 nm and in nanocrystals of CdS (crystallized in the transparent molecular filter—mica with empty channels of designed diameter). The induced decrease of absorption in quantum wires has been explained by filling of the size-quantized energy bands with nonequilibrium carriers (saturation effect) and by the phase-space filling of excitons. 相似文献
8.
L. J. Anderson M. V. Jacob M. Barra F. V. Di Girolamo A. Cassinese 《Applied Physics A: Materials Science & Processing》2011,105(1):95-102
Thin films of the n-type, organic semiconductor PDI-8CN2 were thermally evaporated on two different dielectric surfaces and their optical and morphological properties investigated
using Variable Angle Spectroscopic Ellipsometry (VASE) and Atomic Force Microscopy (AFM), respectively. The two dielectric
surfaces used were SiO2 and a plasma polymer derived from the non-synthetic monomer linalyl acetate. The characterisations were performed in order
to assess the viability of plasma polymerised linalyl acetate (PLA) thin films as dielectric layers in future Organic Field-Effect
Transistor (OFET) devices. These studies resulted in determination of the optical profiles (refractive index and extinction
coefficient) in the UV-Vis band of PDI-8CN2 grown on SiO2 and an observation of uniaxial anisotropy in the organic semiconductor. This information is useful for the design of opto-electronic
devices using PDI-8CN2 layers. Variations in morphological properties and small variations optical properties were found when the PDI-8CN2 films were grown on PLA layers, and attributed to the change in surface chemistry between dielectrics. 相似文献
9.
M. E. Kompan I. Yu. Sapurina V. Babayan N. E. Kazantseva 《Physics of the Solid State》2012,54(12):2400-2406
Different forms of an electrically conductive polymer, an organic semiconductor, namely, polyaniline, have been synthesized and characterized. The magnetization curves of the obtained forms have been analyzed. It has been found that, in the oxidized form, the material exhibits a magnetic hysteresis at room temperature. For polyaniline without a special doping with magnetic additives, this result has been obtained for the first time. The possibility of controlling the magnetic properties of the material by means of chemical treatment at the post-polymerization stage has been demonstrated. 相似文献
10.
A. B. Fedotov A. M. Zheltikov L. A. Mel’nikov A. P. Tarasevitch D. von der Linde 《JETP Letters》2000,71(7):281-284
Changes in the spectra of femtosecond laser pulses propagating through fibers with a cladding having the structure of a two-dimensional photonic crystal are experimentally investigated. It is demonstrated that the waveguide properties of defect modes of photonic-crystal fibers provide an opportunity to considerably increase the efficiency of spectral broadening of short laser pulses as compared with conventional fibers. 相似文献
11.
Abstract The field of nonlinear optics is briefly introduced, followed by a review of quantum size effects in small semiconductor particles, with special reference to the linear and nonlinear optical properties. Experimental methods, especially the “laser induced grating” technique are described. Semiconductor (CdS x Se1?x ) doped glasses are examined, both the commercially available niters and a specially made experimental CdSe doped glass. Both linear and nonlinear optical properties are discussed. Colloidal and polymers systems are also briefly discussed. 相似文献
12.
13.
本文给出了在环形光纤外腔光反馈之下半导体激光器频偏特性的小信号分析理论.分析表明,尤其在千兆赫以下的调制频段中,耦合腔相移、内外腔光耦合强度及内外腔光场相位失谐对频偏功率比均有显著影响.可望用作强度调制直接检测高速率、长距离光纤通信系统中的光源. 相似文献
14.
Eduard G. Karpov 《哲学杂志》2013,93(10):1300-1316
This work provides a discussion of bistability conditions, switching autowave properties and emergence of dissipative structures in semiconducting fibers with anomalous positive dependence of electrical resistivity on temperature of sigmoid type, (1?+?e ?T )?1. An open system thermodynamics approach is utilized for the analysis of this dissipative solid-state system. The approach aims to represent the structure of the solution space of its governing equation in the form of physical phase diagrams, known as non-equilibrium phase diagrams, and two specific binary diagrams have been obtained here. One of the diagrams, where the electrical power density and ambient temperature represent external parameters, shows a wide region with dissipative structures as non-uniform steady-state temperature profiles on the fiber. The possibility of efficient external control over the dissipative structure geometry is also demonstrated. 相似文献
15.
16.
A.M. Zheltikov 《Applied physics. B, Lasers and optics》2006,84(1-2):69-74
Arrays of submicron air holes are shown to modify the properties of guided modes in optical fibers, enabling a fine tuning
of fiber dispersion, nonlinearity, and gain. We demonstrate fiber dispersion nanomanagement solutions that provide ultra-flattened
group-velocity dispersion profiles and control the fiber nonlinearity and gain.
PACS 42.65.Wi; 42.81.Qb
An announcement to this article was published online March 9, 2007 with DOI . 相似文献
17.
The radiative corrections of nanostructures are investigated by applying a nonlocal theory to a model of semiconductor spheres which are assembled one-, two- and three-dimensionally. An approximate sum rule for radiative corrections and the relation between finite and infinite lattices are given. It is shown that radiative correction strongly depends on the shape as well as the size. For a linear chain, the radiative correction gets saturated when the system length becomes comparable to the wavelength of resonant light. For cubic systems, the radiative width deviates from the size linearity for a surprisingly small size. The two-dimensional case is marginal. This peculiar shape dependence originates from the dipole-dipole interaction. 相似文献
18.
In this article we review the experimental and theoretical investigations of the linear and nonlinear optical properties of semiconductor quantum well structures, including the effects of electrostatic fields, extrinsic carriers and real or virtual photocarriers. 相似文献
19.
E. E. Serebryannikov A. M. Zheltikov N. Ishii C. Y. Teisset S. Köhler T. Fuji T. Metzger F. Krausz A. Baltuška 《Applied physics. B, Lasers and optics》2005,81(5):585-588
Raman soliton phenomena in photonic crystal fibers are shown to allow efficient tunable frequency shifting of sub-10-fs laser pulses. Soliton self-frequency shift in a photonic-crystal fiber with a core diameter less than 2 μm is used to transform the spectrum of a 6-fs 2-nJ Ti: sapphire-laser pulse, dominated by a 670-nm peak, into a spectrum featuring a well-resolved intense spectral component centered at 1064 nm, which is ideally suited as a seed for Nd: YAG- and ytterbium-based laser devices. 相似文献
20.
Coherent anti-Stokes Raman scattering (CARS) is used to measure relations between the resonant (Raman) and nonresonant (Kerr-type) optical nonlinearities of air-guided modes in a hollow-core photonic-crystal fiber (PCF). We demonstrate that, due to its interference nature, CARS provides a convenient tool for measuring the contribution of the fiber cladding to the total nonlinearity sensed by air-guided modes in hollow PCFs. On a Raman resonance with molecular vibrations in the gas that fills the fiber core, a two-color laser field is shown to induce optical nonlinearities that are several orders of magnitude higher than the nonresonant Kerr-type nonlinearities typical of air-guided PCF modes. 相似文献