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We investigate the properties of waveguides induced by one-dimensional grey
screening solitons in biased photorefractive crystals. The results show that
waveguides induced by grey screening solitons are always of single mode for all
intensity ratios, i.e. the ratios between the peak intensity of the
soliton and the dark irradiance. Our analysis indicates that the
energy confined near the centre of the grey soliton and the propagation constant of
the guided mode of the waveguide induced by the grey screening soliton
increase monotonically with intensity ratio increasing. On the other hand,
when the soliton greyness increases, the energy confined near the centre
of the grey soliton and the propagation constant of the guided mode of the
waveguide induced by the grey screening soliton decrease monotonically.
Relevant examples are provided where photorefractive crystal is of the
strontium barium niobate type. 相似文献
26.
为了实现高双折射光子晶体光纤,提出了一种在纤芯中引入微小圆孔的方法.利用全矢量有限元方法和完美匹配层条件研究了基于圆孔微细结构纤芯的光子晶体光纤的双折射特性.讨论了纤芯圆孔数量、孔径、间隔距离对光纤双折射特性的影响;设计了一种双折射达到10-2量级的光子晶体光纤.模拟结果表明采用三个以上圆孔可以获得较大的双折射,增大外包层数目可以有效减小约束损耗. 相似文献
27.
Photonic Crystal Fiber Source of Quantum Correlated Photon Pairs in the 1550nm Telecom Band 下载免费PDF全文
A source of quantum correlated photon pairs in the 155Onto telecom band obtained by a pumping 11 m photonic crystal fiber with lOps pulse trains is experimentally demonstrated. We investigate how the birefringence of the fiber influences the purity of the photon pairs. We also present the frequency correlation of the signal and idler photon pairs. The experimental results are useful for developing a compact source of photon pairs well suited for quantum communication. 相似文献
28.
Design on a highly birefringent and nonlinear photonic crystal fiber in the C waveband 总被引:1,自引:0,他引:1 下载免费PDF全文
In this paper, a novel photonic crystal fiber (PCF) with high birefringence and nonlinearity is designed. The charac- teristics of birefringence, dispersion and nonlinearity are studied by using the full-vector finite element method (FVFEM). The numerical results show that the phase birefringence and nonlinear coefficient of PCF can be up to 4.51× 10-3 and 32.8972 w-l.km-1 at 1.55 μm, respectively. The proposed PCF could be found to have important applications in the polarization-dependent nonlinear optics such as the pulse compress and reshaping in the C waveband. 相似文献
29.
Enhanced pulse compression induced by the interaction between the third—order dispersion and the cross—phase modulation in birefringent fibres 总被引:1,自引:0,他引:1 下载免费PDF全文
In this paper,we report on the enhanced pulse compression due to the interaction between the positive third-order dispersion (TOD) and the nonlinear effect (cross-phase modulation effect) in birefringent fibres.Polarization soliton compression along the slow axis can be enhanced in a birefringent fibre with positive third-order dispersion,while the polarization soliton compression along the fast axis can be enhanced in the fibre with negative third-order dispersion.Moreover,there is an optimal third-order dispersion parameter for obtaining the optimal pulse compression.Redshifted initial chirp is helpful to the pulse compression,while blueshifted chirp is detrimental to the pulse compression.There is also an optimal chirp parameter to reach maximum pulse compression.The optimal pulse compression for TOD parameters under different N-order solitons is also found. 相似文献
30.
Optimization of highly nonlinear dispersion-flattened photonic crystal fiber for supercontinuum generation 下载免费PDF全文
A simple type of photonic crystal fiber (PCF) for supercontinuum generation is proposed for the first time. The proposed PCF is composed of a solid silica core and a cladding with square lattice uniform elliptical air holes, which offers not only a large nonlinear coefficient but also a high birefringence and low leakage losses. The PCF with nonlinear coefficient as large as 46 W 1 · km-1 at the wavelength of 1.55 μm and a total dispersion as low as ±2.5 ps · nm-1 · km-1 over an ultra-broad waveband range of the S-C-L band (wavelength from 1.46 μm to 1.625 μm) is optimized by adjusting its structure parameter, such as the lattice constant Λ , the air-filling fraction f , and the air-hole ellipticity η. The novel PCF with ultra-flattened dispersion, highly nonlinear coefficient, and nearly zero negative dispersion slope will offer a possibility of efficient super-continuum generation in telecommunication windows using a few ps pulses. 相似文献