共查询到20条相似文献,搜索用时 15 毫秒
1.
L. R. Jaroszewicz M. Murawski T. Nasilowski K. Stasiewicz P. Mar? M. Szymański P. Mergo 《Opto-Electronics Review》2011,19(2):256-259
We report the methodology of effective low-loss fusion splicing a photonic crystal fibre (PCF) to itself as well as to a standard
single mode fibre (SMF). Distinctly from other papers in this area, we report on the results for splicing suspended core (SC)
PCF having tiny core and non-Gaussian shape of guided beam. We show that studied splices exhibit transmission losses strongly
dispersive and non-reciprocal in view of light propagation direction. Achieved splicing losses, defined as larger decrease
in transmitted optical power comparing both propagation directions, are equal to 2.71 ±0.25 dB, 1.55 ±0.25 dB at 1550 nm for
fibre SC PCF spliced to itself and to SMF, respectively. 相似文献
2.
Photonic Crystal Circuits have been widely investigated for various optoelectronics device applications. And the gratings in photonics devices are indispensable tool, which is very common for light manipulation. In this study, an interference grating structure formed by Gaussian beam interferences in photonic crystal waveguide such that having Kerr type nonlinearity is proposed and its transmission characteristics are investigated. Finite-Difference Time-Domain method is used to analyze the device characteristics. According to simulation results, the interference grating has shown special transmission characteristics that can bring tunability for photonic crystal devices. This can be an effective method for controlling optical signals in the photonic crystal for all optical switching/routing applications as a part of add/drop multiplexing. 相似文献
3.
The modal characteristics of silica-based photonic crystal fibres (PCF) are examined through a scalar modal analysis combined with an effective V-parameter model using a finite-difference method. Cut off frequencies of the lowest-order modes and the normalised dispersion curves are given and are found to be quasi-independent of the hole-size-to-pitch ratio. A simple and accurate empirical relation for the cutoff wavelength is given for the first higher-order mode for fibres with hole-size-to-pitch ratio below 0.7. These results should be very useful in designing PCF's for various applications. 相似文献
4.
Using the finite element method, this paper investigates lateral
stress-induced propagation characteristics in a photonic crystal
fibre of hexagonal symmetry. The results of simulation show the
strong stress dependence of effective index of the fundamental
guided mode, phase modal birefringence and confinement loss. It also
finds that the contribution of the geometrical effect that is
related only to deformation of the photonic crystal fibre and the
stress-related contribution to phase modal birefringence and
confinement loss are entirely different. Furthermore,
polarization-dependent stress sensitivity of confinement loss is
proposed in this paper. 相似文献
5.
The periodic array of air holes in the cladding of a photonic crystal fibre (PCF) provides a convenient scaffold for the introduction of an infiltrating liquid. In this paper we demonstrate a novel platform of one-dimensional tuneable nonlinear photonic lattices produced by selectively infiltrating a row of holes in a PCF. Such structures have been realised by blocking individual holes on one end of a PCF, leaving the desired infiltration pattern unblocked. Unblocked holes are then infiltrated by immersing the unblocked end of the fibre in a reservoir of the infiltrating liquid, allowing for the realisation of a wide variety of periodic structures. Such structures are studied for traditional linear and nonlinear effects in periodic systems. 相似文献
6.
Temperature dependence of birefringence in olarization-maintaining photonic crystal fibres 下载免费PDF全文
In this paper,the temperature dependence of birefringence in polarization maintaining photonic crystal fibres(PMPCFs) is investigated theoretically and experimentally.Utilizing the structural parameters of the PM-PCF samples in the experiment,two effects leading to the birefringence variation under different temperatures are analysed,which are the thermal expansion of silica material and the refractive index variation due to the temperature variation.The actual birefringence variation of the PM-PCF is the combination of the two effects,which is in the order of 10-9 K-1 for both fibre samples.Calculation results also show that the influence of refractive index variation is the dominant contribution,which determines the tendency of the fibre birefringence variation with varying temperature.Then,the birefringence beat lengths of the two fibre samples are measured under the temperature,which varies from -40℃ to 80℃.A traditional PANDA-type polarization maintaining fibre(PMF) is also measured in the same way for comparison.The experimental results indicate that the birefringence variation of the PM-PCF due to temperature variation is far smaller than that of the traditional PMF,which agrees with the theoretical analysis.The ultra-low temperature dependence of the birefringence in the PM-PCF has great potential applications in temperature-insensitive fibre interferometers,fibre sensors,and fibre gyroscopes. 相似文献
7.
In this paper theoretical and experimental results regarding discrete light propagation in photonic liquid crystal fibres (PLCFs) are presented. Particular interest is focused on tunability of the beam guidance obtained due to the variation in either external temperature or optical power (with assumption of thermal nonlinearity taking place in liquid crystals). Highly tunable (discrete) diffraction and thermal self-(de)focusing are studied and tested in experimental conditions. Specifically, spatial light localization and/or delocalization due to the change in tuning parameters are demonstrated, with possibility of discrete spatial (gap) soliton propagation in particular conditions. Results of numerical simulations (performed for the Gaussian beams of different widths and wavelengths) have been compared to those from experimental tests performed in the PLCFs of interest. Owning to the limit of experimental means, direct qualitative comparison was not quite accessible. Nevertheless, a qualitative agreement between theoretical and experimental data (obtained in analogous conditions) has been achieved, suggesting a compact and widely-accessible platform for the study of tunable linear (and nonlinear) discrete light propagation in two-dimensional systems. Proposed photonic structures are of a great potential for all-optical beam shaping and switching. 相似文献
8.
This paper theoretically studies the double-pumped fibre-optical
parametric amplifiers (FOPAs) in photonic crystal fibres. Two
distinct working regimes of FOPAs are researched, which depend on the
dispersion at the central wavelength of the two pumps. Extremely
broad tuning range can be obtained when the central pump wavelength
is in the normal dispersion regime and is insensitive to the
wavelength separation between the two pumps, while the tuning range
is narrow in the anomalous dispersion regime and can be significantly
enhanced by increasing the wavelength separation. Impacts of
higher-order dispersions and temporal walk-off on the gain spectra
are also discussed. 相似文献
9.
R. Buczynski J. Pniewski D. Pysz R. Stepien R. Kasztelanic I. Kujawa A. Filipkowski A. J. Waddie M. R. Taghizadeh 《Opto-Electronics Review》2012,20(3):207-215
The development of all-solid photonic crystal fibres for nonlinear optics is an alternative approach to air-glass solid core photonic crystal fibres. The use of soft glasses ensures a high refractive index contrast (> 0.1) and a high nonlinear coefficient of the fibres. We report on the dispersion management capabilities in all-solid photonic crystal fibres taking into account four thermally matched glasses which can be jointly processed using the stack-and-draw fibre technique. We present structures with over 450 nm broadband flat normal dispersion and ultra-flat near zero anomalous dispersion below 5 ps/nm/km over 300 nm dedicated to supercontinuum generation with 1540 nm laser sources. The development of an all-solid photonic crystal fibre made of F2 and NC21 glasses is presented. The fibre is used to demonstrate supercontinuum generation in the range of 730?C870 nm (150 nm) with flatness below 5 dB. 相似文献
10.
This paper theoretically studies the double-pumped fibre-optical parametric amplifiers (FOPAs) in photonic crystal fibres. Two distinct working regimes of FOPAs are researched, which depend on the dispersion at the central wavelength of the two pumps. Extremely broad tuning range can be obtained when the central pump wavelength is in the normal dispersion regime and is insensitive to the wavelength separation between the two pumps, while the tuning range is narrow in the anomalous dispersion regime and can be significantly enhanced by increasing the wavelength separation. Impacts of higher-order dispersions and temporal walk-off on the gain spectra are also discussed. 相似文献
11.
We describe the use of tapered hollow-core photonic crystal fibres for delivery and compression of ultrashort optical pulses. We demonstrate delivery of transform-limited pulses with less than 100 fs pulse length and above 50 nJ energy through 8 m of fibre, in a single transverse mode. 相似文献
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13.
Maciej Antkowiak Rafał Kotyński Krassimir Panajotov Francis Berghmans Hugo Thienpont 《Optical and Quantum Electronics》2007,39(4-6):455-467
We study numerically the temporal and spatial dynamics of light in Bragg gratings in highly nonlinear photonic crystal fibre
for a CW input signal. Our numerical model is based on the plane wave mode solver and a set of nonlinear coupled-mode equations
which we solve using a variation of implicit fourth order Runge-Kutta method. We observe not only bistability of the intensity
versus transmitted and reflected light but also complex dynamics. We demonstrate that for values of input intensity above
the bistable region the steady state may undergo a supercritical Hopf bifurcation. For some ranges of the input intensity
we also observe a coexistence of two periodic attractors. The dynamics found, in particular the features in the bifurcation
diagram, strongly depend on the parameters of the fibre. Consequently, we suggest that by proper design of the photonic crystal
in the cladding we can adjust such nonlinear features of the Bragg gratings as the width of the bistable region, the intensity
at which the bifurcation occurs and also the characteristics of the dynamics at high values of input intensity. 相似文献
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17.
H. C. Nguyen B. T. Kuhlmey E. C. Mägi M. J. Steel P. Domachuk C. L. Smith B. J. Eggleton 《Applied physics. B, Lasers and optics》2005,81(2-3):377-387
Microstructured optical fibres (MOFs) have attracted much interest in recent times, due to their unique waveguiding properties that are vastly different from those of conventional step-index fibres. Tapering of these MOFs promises to significantly extend and enhance their capabilities. In this paper, we review the fabrication and characterisation techniques of these fibre tapers, and explore their fundamental waveguiding properties and potential applications. We fabricate photonic crystal fibre tapers without collapsing the air-holes, and confirm this with a non-invasive probing technique that enables the characterisation of the internal microstructure along the taper. We then describe the fundamental property of such tapers associated with the leakage of the core mode that leads to long-wavelength loss, influencing the operational bandwidth of these tapers. We also revisit the waveguiding properties in another form of tapered MOF photonic wires, which transition through waveguiding regimes associated with how strongly the mode is isolated from the external environment. We explore these regimes as a potential basis for evanescent field sensing applications, in which we can take advantage of air-hole collapse as an extra dimension to these photonic wires. 相似文献
18.
提出了一种适用于毫米波及THz波行波放大器的光子晶体栅慢波电路,即横向分布光子晶体栅慢波电路,并提出了分析和设计此类光子晶体栅慢波电路的方法.通过计算光子晶体TE极化的带隙和在带隙内将光子晶体栅慢波电路等效为矩形栅波导慢波电路,从而,光子晶体栅慢波电路的设计得以分为两步独立进行,从而简化了光子晶体栅慢波电路的设计.对横向分布光子晶体栅慢波电路进行了设计和计算,结果表明,与矩形栅波导慢波电路相比,横向分布光子晶体栅慢波电路可以降低工作电压并增加带宽,从而可以降低成本.
关键词:
行波放大器
光子晶体
毫米波
慢波电路 相似文献
19.
We study higher-order nonlinear modes in the form of vortex solitons and soliton clusters propagating in the waveguides created
in photonic crystal fibers made of a material with the focusing Kerr nonlinearity. We find numerically different families
of such nonlinear modes with a nontrivial topology and study their bifurcations. We also study the soliton stability to propagation.
We demonstrate that waveguides in photonic crystal fibers may support a variety of soliton clusters with the symmetries that
may differ from the lattice symmetry. We also discuss briefly the case of a dual-core coupler created by two neighboring cores
in a photonic crystal fiber and find numerically the profiles of symmetric and asymmetric nonlinear modes. 相似文献
20.
Reported are experimental results from investigations of the sensing properties of long-period gratings (LPGs) recorded in two different geometries of photonic crystal fibre (PCF): a large-mode area PCF and an endlessly single mode PCF. The LPGs have been characterised for their sensitivity to temperature, bending, surrounding index and strain. The LPGs in both fibres have been found to have negligible temperature sensitivity whilst exhibiting useful strain sensitivities. Strong directional bend sensitivity is shown by one PCF whilst the other shows good non-directional bend sensitivity. The fibres exhibit differing sensitivities to surrounding refractive index. 相似文献