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ZHANG Yan-jun GAO Hao-lei FU Xing-hu TIAN Yong-sheng WANG Hui-min ZHANG Yi-nan 《光谱学与光谱分析》2018,38(1):285-289
受激布里渊散射会影响少模光纤传输系统中的信噪比、传输距离与传输容量,是影响传输系统入纤功率提高的重要因素。对阶跃型少模光纤的受激布里渊散射谱的阈值进行了研究,运用了布里渊散射谱、模式联运谱的数学模型对少模光纤散射特性进行了分析,探讨了少模光纤布里渊散射增益谱、阈值增益系数,以及光纤各参量对少模光纤阈值的影响。分析结果表明:SI-10阶跃型少模光纤中存在五种不同的传播模式,不同模式有各自的传输常数以及有效折射率,各模式相互作用导致模式展宽、增益降低,且布里渊散射谱峰值增益系数为3.9×10-11 m·W-1。阈值增益系数受到光纤传感距离的影响,在相对较短距离传输中阈值急速下降,且其趋势随长度增加渐趋平缓,当光纤长度达到22 km时阈值增益系数趋于常数18.1。少模光纤的阈值因光纤长度的递增而递减,且递减趋势渐缓趋于常数20.5 dBm;少模光纤不同模式受激布里渊散射的阈值也因光纤长度的递增而递减最终趋于常数,且不同模式的阈值因模式阶数的递增而递增;少模光纤的阈值随着光纤衰减系数和纤芯半径的递增而递增,且增加趋势缓慢增大。不同衰减系数的光纤其阈值在不同长度趋于常数,衰减系数越大受激布里渊散射阈值越大越容易趋于一常数。 相似文献
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Stimulated Brillouin scattering-induced phase noise in an interferometric fiber sensing system 下载免费PDF全文
Stimulated Brillouin scattering-induced phase noise is harmful to interferometric fiber sensing systems. The localized fluctuating model is used to study the intensity noise caused by the stimulated Brillouin scattering in a single-mode fiber. The phase noise structure is analyzed for an interferometric fiber sensing system, and an unbalanced Michelson interferometer with an optical path difference of 1 m, as well as the phase-generated carrier technique, is used to measure the phase noise. It is found that the phase noise is small when the input power is below the stimulated Brillouin scattering threshold, increases dramatically at first and then gradually becomes flat when the input power is above the threshold, which is similar to the variation in relative intensity noise. It can be inferred that the increase in phase noise is mainly due to the broadening of the laser linewidth caused by stimulated Brillouin scattering, which is verified through linewidth measurements in the absence and presence of the stimulated Brillouin scattering. 相似文献
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Stimulated Brillouin scattering-induced phase noise in an interferometric fiber sensing system 下载免费PDF全文
Stimulated Brillouin scattering-induced phase noise is harmful to interferometric fiber sensing systems.The localized fluctuating model is used to study the intensity noise caused by the stimulated Brillouin scattering in a single-mode fiber.The phase noise structure is analyzed for an interferometric fiber sensing system,and an unbalanced Michelson interferometer with an optical path difference of 1 m,as well as the phase-generated carrier technique,is used to measure the phase noise.It is found that the phase noise is small when the input power is below the stimulated Brillouin scattering threshold,increases dramatically at first and then gradually becomes flat when the input power is above the threshold,which is similar to the variation in relative intensity noise.It can be inferred that the increase in phase noise is mainly due to the broadening of the laser linewidth caused by stimulated Brillouin scattering,which is verified through linewidth measurements in the absence and presence of the stimulated Brillouin scattering. 相似文献
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A XeCl laser system without dispersive elements is used to investigate near threshold reflectivity and phase-conjugation (PC) fidelity of stimulated Brillouin scattering (SBS) mirrors with SF6 as the active medium. Using different focal-length lenses to focus the broadband laser radiation into the Brillouin medium, it was found that at threshold the effective interaction length for SBS is equal to the confocal parameter and that the SBS gain is equal to its steady-state value for monochromatic pumping. High PC-fidelity values ranging from 0.8–1.0 were found under most of the experimental conditions investigated. 相似文献
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近年来,光纤布拉格光栅传感器与全分布式光纤传感器的融合技术受到了广泛关注,然而光纤布拉格光栅与布里渊信号之间的耦合特性鲜有报道。本文研究了光栅类型、波长、反射率及光纤的光致折射率对受激布里渊信号的影响规律,并探讨了空间分辨率对光纤布拉格光栅定位功能的影响。实验结果表明,在布里渊光时域分析系统中,光纤布拉格光栅处有尖锐的反射峰,而啁啾光栅、长周期光栅及光致折射率变化的光纤处均未出现尖锐的反射峰;光纤布拉格光栅反射率与受激布里渊散射功率谱无关;当光纤布拉格光栅的波长接近1 550 nm时,对受激布里渊频移测量的影响最大;在8 m的长度范围内,光纤布拉格光栅的定位误差约为4 cm,并且与空间分辨率无关。 相似文献
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We demonstrate a new and simple solution to suppress stimulated Brillouin scattering in fiber optical parametric amplifiers. Cumbersome PRBS or sinusoidal generators used to broaden the pump spectrum are replaced by a filtered microwave noise source. Stimulated Brillouin scattering threshold can be increased up to large values still keeping an excellent quality of amplification of nonreturn to zero signals. The simplicity and the performances of this setup open the way for a wide variety of applications for FOPAs. 相似文献
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A numerical and experimental analysis of the stimulated Brillouin scattering in a single-mode optical fiber for distributed sensing applications is carried out in the frequency domain. The theoretical model describing the Brillouin interaction is solved by taking into account the temporal dynamics of the acoustic wave that is involved. The simulations and the experimental results reveal the role played by the ac component of the acoustic wave, which is responsible for significant changes of the small-signal stimulated Brillouin scattering transfer function that occur when the modulation frequency rises above the natural Brillouin gain spectrum linewidth. One should take these effects into account to perform accurate signal processing of frequency-domain signals in high-resolution distributed sensing applications. 相似文献
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We demonstrate the passive suppression of stimulated Brillouin scattering in meter-length fiber-ring cavities through careful control of the fiber length. Experimentally we are able to demonstrate an over sixty-times increase in the Brillouin threshold of a 0.4 m fiber ring. This very simple suppression technique greatly simplifies the design of optical parametric devices based on fiber-ring cavities. 相似文献
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提出了一种新型的由熔石英棒和石英光纤组成的复合型相位共轭镜,其可运用于高重复频率激光输入系统中以改善光束质量.该复合相位共轭镜具有较高的受激布里渊散射反射率和受激布里渊散射损伤阈值以及较低的受激布里渊散射阈值等优点.实验中,在100 Hz重复频率下,最大获得了42.05%的受激布里渊散射反射率.根据实验条件,由耦合波方程及边界条件得到的物理模型,经数值求解后得到的结果和实验符合较好.且由理论结果提出了一种提高该复合型相位共轭镜工作状态的有效方法.
关键词:
复合型相位共轭镜
受激布里渊散射
熔石英
耦合波方程 相似文献
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S. Ghosh Nishchhal Yadav 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,59(2):173-178
Using the hydrodynamical model and following the coupled mode approach, detailed analytical investigation of stimulated Brillouin
scattering is performed in an electrostrictive semiconductor. The total induced current density including diffusion current
density and the effective Brillouin susceptibility are obtained under off-resonant laser irradiation. The analysis deals with
the qualitative behaviour of the Brillouin gain and transmitted intensity with respect to excess doping concentration and
magnetic field. Efforts are directed towards optimizing the doping level and magnetic field to achieve maximum Brillouin gain
at pump intensities far below the optical damage threshold level. It is found that by immersing a moderately doped semiconductor
in a sufficiently strong magnetic field in transverse direction, one can achieve resonant enhancement of Brillouin gain provided
the generated acoustic mode lies in the dispersionless regime. 相似文献
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An optical fibre intensity sensor referenced by stimulated Brillouin scattering is presented. The optical sensor uses Fresnel reflection signal at the sensor fibre end and employs an adequate relationship between Brillouin and Rayleigh scattering and Fresnel reflection to have a referenced optical fibre intensity sensor addressed in reflection. 相似文献
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We propose and investigate an accurate method for the experimental measurement of the stimulated Brillouin scattering gain coefficient in optical fiber. The gain is extracted from measuring the transmitted pump power at the threshold of stimulated Brillouin scattering (SBS) laser oscillation in a Fabry-Perot cavity formed by Fresnel reflection at the fiber ends. The method is free from a range of uncertainties and difficulties of commonly used approaches and is easy to implement. Experimental evidence of the variation of the SBS gain coefficient with numerical aperture of the fiber, first predicted in [Phys. Rev. Lett. 85, 1879 (2000)], is proven. 相似文献
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Stimulated Brillouin scattering is studied by numerically solving the Vlasov-Maxwell system. A cascade of stimulated Brillouin scattering can occur when a linearly polarized laser pulse propagates in a plasma. It is found that a stimulated Brillouin scattering cascade can reduce the scattering and increase the transmission of light, as well as introduce a bursting behaviour in the evolution of the laser-plasma interaction. The bursting time in the reflectivity is found to be less than half the ion acoustic period. The ion temperature can affect the stimulated Brillouin scattering cascade, which can repeat several ×at low ion temperatures and can be completely eliminated at high ion temperatures. For stimulated Brillouin scattering saturation, higher-harmonic generation and wave-wave interaction of the excited ion acoustic waves can restrict the amplitude of the latter. In addition, stimulated Brillouin scattering cascade can restrict the amplitude of the scattered light. 相似文献
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Y. G. Shee M. A. Mahdi M. H. Al-Mansoori A. Ismail N. A. M. A. Hambali A. K. Zamzuri R. Mohamad S. Yaakob 《Laser Physics》2009,19(12):2194-2196
A simple configuration for the reduction of stimulated Brillouin scattering threshold in photonic crystal fiber is presented.
The threshold reduction is contributed by the bidirectional pumping scheme through the reflection of transmitted Brillouin
pump back to the gain medium. The pump recycling scheme has greatly reduced the Brillouin threshold of a 200-m long of photonic
crystal fiber from 50 to 30 mW of Brillouin pump power. 相似文献
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Temporally stable high-fidelity optical phase conjugation by stimulated Brillouin scattering of cw laser radiation is achieved in multimode silica fiber with cavity feedback. A power threshold of approximately 500 mW and a reflectivity of 70% were obtained in a 340-m-long fiber with a cw Nd:YAG laser. 相似文献
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Efficient single-mode Brillouin fiber laser for low-noise optical carrier reduction of microwave signals 总被引:2,自引:0,他引:2
We experimentally demonstrate efficient optical carrier reduction of microwave signals with a single-mode 1.5-microm wavelength Brillouin all-fiber ring laser. Because of the tunable optical coupling, the lasing threshold of the short-length (20-m) fiber cavity is lower than 5 mW, and high conversion efficiencies (up to 60%) are obtained at any pump power up to approximately 200 mW. Using the single-mode Stokes beam as a seed for the stimulated Brillouin scattering process allows up to 40-dB optical carrier depletion with almost no added noise for an optically carried microwave signal at 6 GHz. In addition, using this resonator, we provide evidence of generation of high-spectral-purity beatnotes. 相似文献