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Photonic crystal fibres (PCFs) offer new possibilities of realizing highly birefringent fibres due to a higher intrinsic index contrast compared to conventional fibres. In this paper, we analyse theoretically the modal properties of a kind of polarization-maintaining PCF, namely the elliptical hole photonic crystal fibre (EHPCF) with a central small elliptical hole introduced in the core region. We demonstrate the possibility of achieving large birefringence with zero walk-off in the single-mode regime. This PCF also exhibits unusual dispersion properties. Several hundred nanometres of ultra broadband flattened dispersion near the wavelength 1.55μm is achieved in this EHPCF with a central small hole of d_c=0.4Λ. 相似文献
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High birefringence, low loss terahertz photonic crystal fibres with zero dispersion at 0.3 THz 下载免费PDF全文
A terahertz photonic crystal fibre (THz-PCF) is designed for terahertz wave propagation. The dispersion property and model birefringence are studied by employing the finite element method. The simulation result reveals the changing patten of dispersion parameter versus the geometry. The influence of the large frequency band of terahertz on birefringence is also discussed. The design of low loss, high birefringence THz-PCFs with zero dispersion frequency at 0.3 THz is presented. 相似文献
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A compact two-stage optical parametric chirped pulse amplifier based on photonic crystal fibre is demonstrated.A 1064-nm soliton pulse is obtained in a home-made photonic crystal fibre (PCF) with femtosecond pulse pumping and then amplified to 2 mJ in an Nd:YAG regenerative amplifier.After the amplified pulses pass through the LBO crystal,the 532-nm double-frequency light with an energy of 0.8 mJ and a duration of over 100 ps at 10-Hz repetition rate is generated as a pump source in the following two-stage optical parametric amplification (OPA).The 850-nm chirped signal light gain from the stretcher is 1.5×10 4 in the first-stage OPA while it is 120 in the second-stage OPA.The total signal gain of optical parametric chirped pulse amplification (OPCPA) can reach 1.8×10 6. 相似文献
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Improved high birefringence photonic crystal fibres with dispersion flattened and single mode operation 下载免费PDF全文
A kind of improved high birefringence photonic crystal fibre (PCF) is proposed in this paper. The characteristics of birefringence, dispersion and leakage loss are studied by the multipole method. Numerical results show that the improved PCF possesses the properties of a flat dispersion and single mode operation. Moreover, with the operating wavelength λ = 1.55μm, the modal birefringence increases greatly in comparison with that of the original PCF, and the leakage loss is about 104 times smaller than that of the original PCF because the modification gives rise to the strong confinement of guided modes. It is expected that the improved PCF can be used as high birefringence and dispersion flattened fibres. 相似文献
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设计了一种高双折射高非线性纳米结构光子晶体光纤,利用电磁场散射的多极理论研究了这种光纤的双折射、基模模场、色散以及非线性特性.数值研究发现,加大纤芯及包层空气孔的非对称程度,可使双折射变大,其双折射最大值可达1.918×10-2.通过调节孔节距大小,可将双折射最大值调至所需波长处,孔节距为400nm的纳米光子晶体光纤在800nm波长处非线性系数高达0.2m-1.W-1,同时在750—1000nm的波段有较大的双折射值,高双折射和高非线性在纳米结构光子晶体光纤中实现了完美的结合.对新型纳米光子器件的研制和集成光学的发展具有重要意义. 相似文献
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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
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Photonic crystal, a novel and artificial photonic material with periodic dielectric distribution, possesses photonic bandgap
and can control the propagation states of photons. Photonic crystal has been considered to be a promising candidate for the
future integrated photonic devices. The properties and the fabrication method of photonic crystal are expounded. The progresses
of the study of ultrafast photonic crystal optical switching are discussed in detail. 相似文献
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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
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提出了一种兼具低损耗、宽带近零色散和高非线性的光子晶体光纤结构,该结构光纤包层空气孔直径从纤芯向外层方向渐进增加;应用多极法,通过改变包层空气孔间距Λ、各层空气孔直径和空气孔层数Nr,对光子晶体光纤色散、损耗和非线性特性进行分析,获得了各特性随包层结构参数变化的规律,并最终设计出最佳结构参数。计算结果表明,该结构光纤存在3个零色散点,在1.25~1.55 μm较宽的波长范围内,色散值波动小于0.27 ps·nm−1·km−1,色散斜率小于0.008 ps·km−1·nm−2,1.55 μm波长处损耗为0.021 dB/km,在常用的飞秒激光泵浦波长0.8,1.06,1.55 μm处非线性系数分别达到78.6,60.4,38.2 W−1·km−1。 相似文献
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This paper reports that, based on the electromagnetic
scattering theory of the multipole method, a high-quality hollow beam is
produced through a selectively liquid-filled photonic crystal fibre.
Instead of a doughnut shape, a typical hollow beam is produced by
other methods; the mode-field images of the hollow-beam photonic
crystal fibre satisfy sixth-order rotation symmetry, according to
the symmetry of the photonic crystal fibre (PCF) structure. A dark
spot size of the liquid-filled photonic crystal fibre-generated
hollow beam can be tuned by inserting liquid into the cladding region
and varying the photonic crystal fibre structure parameters. The
liquid-filled PCF makes a convenient and flexible tool for the
guiding and trapping of atoms and the creation of all-fibre optical
tweezers. 相似文献
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Shubi F. Kaijage Yoshinori Namihira Nguyen H. Hai Feroza Begum S. M. Abdur Razzak Tatsuya Kinjo Hiroki Higa Nianyu Zou 《Optical Review》2008,15(1):31-37
In this paper, we present a dispersion controlling technique with a multiple defect-core hexagonal photonic crystal fiber
(MD-HPCF). By omitting air holes in the core region of the conventional HPCF and adjusting the size of air holes around the
newly formed core, we can successfully design low flattened dispersion PCF with low confinement loss, as well as high birefringence.
The low flattened dispersion feature, as well as the low confinement losses and high birefringence are the main advantages
of the proposed PCF structure, making it suitable as chromatic dispersion controller, dispersion compensator, and/or polarization
maintaining fiber. 相似文献
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设计了一种高双折射高非线性光子晶体光纤, 采用全矢量有限元法研究了这种光纤的基模模场、双折射、非线性、有效模面积及色散特性. 数值研究发现, 减小孔间距Λ的大小, 在波长1550 nm 处, 该光纤可获得10-2 数量级的双折射B, 比普通的椭圆保偏光纤高约两个数量级; 同时, 该光纤可获得42 W-1·km-1 的高非线性系数γ. 另外,分别在可见光和近红外波段出现了两个零色散波长, 在波长800–2000 nm 之间具有良好的色散平坦特性. 这种设计为获得高双折射高非线性超平坦色散光子晶体光纤提供了一种新的方法, 该光纤在偏振控制、非线性光学和色散控制方面具有广泛的应用前景.
关键词:
光子晶体光纤
高双折射
高非线性
有限元法 相似文献
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基于高双折射光子晶体光纤环镜的全光纤平顶梳状滤波器 总被引:1,自引:0,他引:1
A novel all-fibre flat-top comb filter based on a high birefringence photonic crystal fibre loop mirror is proposed and demonstrated. We simulate theoretically its output spectra and experimentally realize a flat-top output with a high extinction ratio. Compared to filters consisting of the conventional Panda polarization main- taining fibre, filters based on a high birefringence photonic crystal fibre loop mirror have better temperature stability. This kind of filter can be expected to be used widely in Wavelength-division-multiplexing(WDM) systems in the future. 相似文献
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A novel all-fibre flat-top comb filter based on a high birefringence photonic crystal fibre loop mirror is proposed and demonstrated. We simulate theoretically its output spectra and experimentally realize a flat-top output with a high extinction ratio. Compared to filters consisting of the conventional Panda polarization maintaining fibre, filters based on a high birefringence photonic crystal fibre loop mirror have better temperature stability. This kind of filter can be expected to be used widely in Wave... 相似文献
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Effect of interstitial air holes on Bragg gratings in photonic crystal fibre with a Ge-doped core 下载免费PDF全文
The effect of interstitial air holes on Bragg gratings in photonic
crystal fibre (PCF) with a Ge-doped core is numerically investigated
by using the beam propagation method (BPM). It is shown that the
interstitial air holes (IAHs) can make Bragg resonance wavelength
λB shift a little towards short wavelengths and
increase λB-λ1 (the wavelength spacing
between the main peak with Bragg resonance wavelength λB and the first side peak with wavelength λ1 and the
coupling coefficient к of Bragg resonance. Moreover, when
the ratio of air hole diameter (d) to pitch (Λ),
d/Λ, is small, IAHs can suppress the cladding mode
resonance. When d/Λ is large, IAHs increase the number
of mode that could strongly interact with the fundamental mode. By
comparing the transmission spectral characteristics of PCF-based
fibre Bragg grating (FBG) with IAHs with those without IAHs at the
same air-filling fraction, it is clarified that the change of
transmission spectral characteristics of PCF-based FBG with IAHs is
not due to a simple change in air-filling fraction. It is also
closely related to the distribution of interstitial air holes. 相似文献
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设计了一种中红外硫系玻璃双芯光子晶体光纤,利用多极法和模式耦合基本理论研究了这种光纤的耦合特性.数值模拟发现,空气孔间距Λ = 5.4 μm,空气孔半径为r = 1.35 μm,空气填充率d/Λ = 0.5的光纤,在归一化波长λ/Λ = 2.04 μm处双折射可以达到0.551×10-2,在归一化波长λ/Λ = 0.93 μm处x偏振方向的耦合长度为145.32 μm,y偏振方向的耦合长
关键词:
双芯光子晶体光纤
硫系玻璃
双折射
耦合长度 相似文献