共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
204 km, 10 Gbit/s standard optical fibre transmission is successfully demonstrated using the mid-span spectral inversion technique with a stimulated Brillouin scattering suppressed fibre phase conjugator, proposed recently by Tani and Yamashita. Transmission performance has been improved compared with a conventional phase conjugator. 相似文献
4.
光子晶体光纤的色散特性 总被引:1,自引:0,他引:1
本文用有效折射率模型 ,分析了光子晶体光纤的色散特性 ,定量给出了光子晶体光纤双折射特性与光纤参数之间的关系 ,指出了光子晶体光纤具有多个零色散波长 ,对相关现象作出了合理的解释。 相似文献
5.
Dispersion compensation with phase-sensitive optical amplifiers 总被引:13,自引:0,他引:13
Recently, we proposed a novel approach to combating the pulse-broadening effect of group-velocity dispersion (GVD) in a fiber-optic communication link (IEEE Photon. Technol. Lett., vol. 5, pp. 669-672, 1993). In our scheme, linear loss in the fiber is balanced by a chain of periodically spaced, phase-sensitive optical amplifiers. In this paper, we present a detailed analysis of pulse propagation in such a fiber line showing that, due to attenuation in the quadrature orthogonal to the amplified quadrature, it is possible for a pulse to propagate without significant broadening over lengths many times longer than the usual dispersion length of the fiber. An averaged equation for pulse evolution over distances longer than the amplifier spacing is derived. The effect of optical-phase fluctuations between the propagating pulse and the amplifiers is also considered. Since our proposed scheme does not rely on the formation of solitons in the fiber, it can be implemented in both the positive and negative GVD regions, and it does not require a minimum peak power for the pulses 相似文献
6.
Much of the currently embedded optical fiber was originally designed for light with a wavelength of 1.3 microns. If this fiber is to be used with tomorrow's optically amplified, high-speed, long span-length lightwave system operating at 1.5 microns, the chromatic dispersion in the fiber must be compensated. Dispersion compensation will be required in long-haul l0 Gb/s systems using conventional fiber. Many compensation techniques have been demonstrated and they exhibit a variety of different and often complimentary properties. Transmitter compensation techniques are the most easily implemented but provide a limited amount of compensation. The most commercially advanced technique is negative dispersion fiber. Chirped Bragg gratings are advancing rapidly, but will always be hampered by their narrow bandwidth. The adoption of any particular technique for use in a high-speed network will depend on the constraints imposed by the, as yet, undefined network architecture 相似文献
7.
A technique for optical pre- or postdistortion in order to compensate for fiber dispersion is discussed theoretically, The dispersion compensation device is based on differential time delay for the upper and the lower sideband of the modulated signal. The proposed scheme is primarily intended for high bit rate (>10 Gbit/s) time division multiplexed transmission, and in an ideal case the transmitting distance could be enhanced by a factor of 4 in a dispersive limited system. With more realistic demands on the dispersion compensation device, the gained distance is in the order of 2.5 相似文献
8.
Dispersion measurement data from two sets of fiber cable lengths were employed to determine the histograms of slope and wavelength of zero chromatic-dispersion in concatenated single-mode fibers. We use a Monte-Carlo technique under two concatenating scenarios, depending on whether those fibers being concatenated are or are not manufactured by the same process. Results show that the variances of slope and wavelength of zero dispersion are inversely proportional to the numberN of fiber cable lengths being concatenated. The average and standard deviation of zero-chromatic dispersion wavelength changes less than 0.005 percent or 1 percent, respectively, when the actual dispersion slopes of individual fiber lengths being concatenated are replaced by random quantities distributed with uniformity within 0.08-0.1 ps/km . nm2. 相似文献
9.
A concept for dispersion compensation in transmission is proposed, based on modes anti-crossing in photonic crystal (PC) line-defect waveguides. Quasi-constant positive and negative dispersion is possible in order of 100 ps/nm/mm on the bandwidth of 100 GHz. An adiabatic taper is proposed for efficient coupling into PC structure. 相似文献
10.
Dispersion compensation by active predistorted signal synthesis 总被引:1,自引:0,他引:1
Techniques for the synthesis of an optical signal predistorted to compensate for fiber dispersion are discussed theoretically. A scheme for very high bit rate (>10 Gbit/s) time-division-multiplexed transmission is proposed which neither requires extremely short pulse sources nor suffers from their inherent dispersion limitations. The rudimentary aspects of the techniques have been verified experimentally by demonstrating both enhanced and degraded transmission of a 4-GHz modulated signal at 1.55 μm over 10-30 km of optical fiber. 相似文献
11.
12.
13.
An overview is given of dispersion measurements on fluoride glasses and fibers, and the dispersion compensating capability of fluoride fibers is discussed. The temperature dependence of refractive-index dispersion and material dispersion of fluoride glasses is measured. These measurements indicate that fluoride glasses can compensate for temperature-dependent changes of refractive indices and material dispersion in silica glasses and fibers 相似文献
14.
为了获得微结构光纤的平坦色散特性,设计了一种圆形排列的微结构光纤,其包层由周期分布的空气孔构成,通过有限元数值分析法对该微结构光纤基模的色散特性进行了数值仿真,研究了色散和纤芯圆孔尺寸以及波长的关系。结果表明:内外空气孔间距和直径对微结构光纤的色散曲线都有影响,但内包层大孔间距和第一圈小空气孔的直径对色散曲线的走向起决定作用。在内圈空气孔直径为3.1μm,其他空气孔直径为1.0μm,内圈空气孔中心间距为5μm,其他空气孔中心间距为4μm时,光纤在1.3μm波长的色散为19.5ps/(nm·km),在1.6μm波长的色散为26.5ps/(nm·km),在1.3~1.6μm波长范围内,其色散值变化范围为7ps/(nm·km)。 相似文献
15.
Dispersion and bandwidth spectra in single-mode fibers 总被引:1,自引:0,他引:1
Bandwidth spectra of single-mode fibers are calculated from experimentally obtained chromatic-dispersion-versus-wavelength curves. Results include second-order effects on bandwidth which depend on the curvature of the dispersion curves. Examples illustrate how bandwidth spectra change as a function of source power spectra. They also show how small changes in fiber dimensions and refractive-index differences can cause significant bandwidth changes at 1.3 μm wavelength. 相似文献
16.
在扫频光源光学相干层析术中,系统和样品中的 色散会影响大深度范围内成像分辨率的保持。本 文提出一种深度相关的色散补偿算法,用于精确补偿样品不同深度处的色散失配。其主要思 想是在干涉光 谱的频域中对样品图像按照不同深度进行分段,随后用基于抛物线法的迭代补偿法在每个深 度处对样品进 行色散补偿。该算法不需要对样品材料信息有预先了解,可在扫频光源光学相干层析系统得 到的光谱中原 位应用。通过在探测深度范围为5.720 mm的扫频光源光学相干层析系 统中对盖玻片堆、损伤KDP晶体 等不同样品进行的实验,证明该算法在全探测深度范围内都能有效提升纵向分辨率并使其接 近理论值,且对于不同种类的样品都有较好的适应性。 相似文献
17.
Taverner D. Richardson D.J. Barcelos S. Zervas M.N. Reekie L. Laming R.I. 《Electronics letters》1995,31(12):1004-1006
The propagation of 16 ps data pulses over 100 km of step-index fibre using two cascaded chirped fibre gratings to achieve dispersion compensation is presented. At the output, the pulses are broadened slightly to 20 ps, indicating the potential for 50 Gbit/s operation 相似文献
18.
We derive analytic expressions for the quadratic and cubic dispersion of optical fiber Bragg gratings, at frequencies far from the Bragg condition, where the usual coupled-mode theory (CMT) fails. We use these to design fibers that have no quadratic dispersion at a particular wavelength, but find that the cubic dispersion then increases. We also show that it is possible to design a fiber link with vanishing average quadratic and cubic dispersion by combining a length of standard fiber and a length of dispersion compensating fiber with an off-resonance grating 相似文献
19.
Krug P.A. Stephens T. Yoffe G. Ouelette F. Hill P. Dhosi G. 《Electronics letters》1995,31(13):1091-1093
A 120 mm long fibre Bragg grating, adjustably chirped by an offset-core technique, compensates for dispersion in a 10 Gbit/s optical communication system operating at 1054 μm over 270 km of non-dispersion-shifted fibre. Simultaneous compensation of fibre dispersion and source chirp in a directly modulated system is also described 相似文献
20.
The equivalence principle is utilized for generation of both incident plane waves and for near- to far-zone transformation in the finite-difference time-domain (FDTD) method. Small errors will appear due to numerical dispersion when a plane wave is generated by Huygens' sources using an analytical expression for the incident field. These errors can be derived from the numerical dispersion relation in the frequency domain. By using a second-order approximation of the numerical wavenumber it is shown that a simple approximative time-domain compensation procedure for the dispersion can be derived. This has been implemented in a Huygens' source routine and in a time-domain near- to far-zone transformation routine. It is shown that this compensation significantly reduces the errors produced when calculating far-zone scattered fields of low amplitude. It is also shown that it is sufficient to compensate either the Huygens' sources or the time-domain near- to far-zone transformation with respect to dispersion. For validation, plane wave propagation through empty space and scattering of a dipole have been studied 相似文献