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1.
We observed an unusually narrow spectrum of Stokes field and Gaussian statistics of Stokes power for the stimulated Brillouin scattering (SBS) process in 300-m single-mode optical fiber with high Rayleigh losses. The measured characteristics of the Stokes radiation indicate that SBS lasing took place in the fiber. The effect is explained as the result of dynamic distributed feedback that is due to double Rayleigh scattering (RS) of the Stokes field. The results of numerical simulation of the cooperative SBS-RS process in fiber are in good agreement with experimental results. 相似文献
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We investigate the nonlinear dynamic behavior of stimulated Brillouin scattering (SBS) near threshold in the absence of feedback. When a cw Nd:YAG laser is injected into a single-mode optical fiber, the SBS signal exhibits intermittently appearing irregular self-pulsations near the threshold. By examining the time series of the SBS signals, we verify that the irregular SBS signal is one of the chaotic phenomena appearing near the bifurcation point. 相似文献
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A high-efficiency hybrid Brillouin/ytterbium fiber laser (BYFL) is demonstrated using a 41.5-cm-longhighly ytterbium-doped fiber and a 10-m-long single-mode optical fiber. The BYFL operates at 1 052.92nm, and the difference between it and the Brillouin pump (BP) wavelength matches the expected stimulated Brillouin scattering (SBS) Stokes shift. Its output power reaches 70.1 mW, which is more than seven times higher than the seeded BP power. The BYFL has an optical signal-to-noise ratio that is greater than 65 dB and has many potential applications, such as in controllable optical delay lines, sensing, and RF photonics. 相似文献
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A method of fabricating colloidal crystal microstructured fiber is presented. The proposed structure relies on partial etching
of the cladding layer of a single-mode fiber and growth of colloidal photonic crystals inside eroded area. The photonic crystal
cylindrical annulus embedded in fiber is characterized by optical and scanning electron microscopy. The optical characterization
was analyzed by optical transmission spectroscopy. The measurement results show a about 1550-nm band gap. The results also
reveal the possibility of cladding cylindrical fibers with three-dimensional photonic crystals. 相似文献
8.
We demonstrate passive combination of multiple beams in an optical fiber via stimulated Brillouin scattering (SBS). Four off-axis beams are combined in a long multimode optical fiber using a novel all-optical mount. The combined beam has the high spatial coherence properties of the LP(01) mode owing to the beam cleanup properties of SBS. The threshold for SBS when off-axis pumps are used is shown to be a factor of 13 times higher than for on-axis pump beams. We propose this method would improve the brightness of an array of fiber amplifiers. 相似文献
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分析了利用光纤中的受激布里渊散射(stimulated Brillouin scattering,SBS)相位共轭效应进行激光腔内调Q,产生ns量级脉冲激光的原理,并对利用该效应产生的激光脉冲波形和脉冲形成过程进行了数值模拟,得到的脉冲波形与SBS相位共轭反射率随时间变化曲线基本一致,表明利用光纤中的SBS相位共轭作用调Q具有可行性.据此,对采用单模光纤(single-mode fiber,SMF)作为SBS池的Er3+掺杂调Q光纤激光器进行实验研究.当单模光纤长度为1.5 m时,在45 mW的光抽运功率下得到脉宽约2.6ns,脉冲周期58.23ns,平均功率7.35mW的激光脉冲.进一步的研究表明:激光器中相位共轭镜的形成与SBS介质长度有关,SBS介质过长,斯托克斯线之间无固定的相位关系,不能形成相干叠加,SBS相位共轭腔不能形成;SBS介质过短,腔内正交偏振模光子寿命的改变使脉冲出现双峰现象.脉冲形成后其属性只与SBS动态属性有关. 相似文献
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对于大功率激光单模光纤远距离传输, 采用传统的受激拉曼散射(SRS)阈值作为注入光纤激光功率值取值过大。本文对单模光纤远距离传输过程中泵浦光和拉曼斯托克斯光(Stokes)光功率随注入光纤激光功率的变化进行仿真与理论分析。根据光纤中SRS产生的机理, 提出以拉曼Stokes光在单模光纤中传输的光功率变化曲线曲率极大值点对应的注入激光功率为限值, 对注入单模光纤光功率限值随着光纤长度变化进行仿真, 通过曲线拟合得出注入单模光纤激光功率限值公式, 并搭建实验系统进行验证。结果表明, 提出的注入单模光纤激光功率限值适用于大功率激光远距离单模光纤传输。 相似文献
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The necessary conditions for nonlinear excitation of higher-order modes in a single-mode step-index optical fiber are analyzed. The cutoff conditions for such an optical waveguide are investigated taking into account Kerr nonlinearity. The minimal power of optical pulses required for fulfilling the necessary conditions for nonlinear excitation of higher-order modes in a single-mode step-index fiber is calculated as a function of the normalized frequency. The allowed ranges of variation of the normalized frequency and optical-radiation power are estimated. It is demonstrated that the conditions necessary for nonlinear excitation of a higher-order mode in a step-index single-mode optical fiber can be created for optical pulses shorter than 500 fs. 相似文献
12.
We demonstrate a 126-W all-fiberized single-mode laser from an 11-μm small-core fiber. The active fiber is a strictly single-mode
fiber that produces pure single-mode. The optical to optical efficiency of the fiber laser is 68.2% with ASE suppressed by
a factor of ∼35 dB and no power-roll. The output power is only limited by the available pump source, scaling the pump power
may achieve much higher output power using the 11 μm small-core fiber. 相似文献
13.
《中国光学快报(英文版)》2016,(12)
The uses of optical fibers are numerous, and over the past few decades, they have extended from optical fiber communications to a wide variety of sensing applications. In particular, fiber Bragg grating(FBG) sensors inscribed in single-mode optical fibers offer significant advantages over more conventional electrical sensors and have been successfully deployed in many different industries. In this Review, we review the applications of intrinsic FBG pressure and flow sensors in oil and gas and the deployment of FBG sensing networks in railways.The promising prospect of using polymer FBGs in wearable medical devices is also described. 相似文献
14.
In this paper we present a novel, time-delay approach using a copper-coated fiber. Piezo optical-fiber stretchers and temperature-controlled fiber spools are normally used for a conventional time-delay lines. A copper-coated fiber preserves the performance of a standard single-mode optical fiber, while at the same time acting as an electrical wire, which can be effectively heated by applying an electrical current. As a result of the significant temperature change, the signal (group) delay can be properly adjusted and controlled. Compared to piezo optical-fiber stretchers and temperature-controlled fiber spools, much shorter lengths of fiber are required and a faster response time can be achieved. This paper also proposes a simple, lumped thermal model and thus a copper-coated fiber can be included in the heat-transfer and response-time calculations of a realistic system that involves surrounding elements (e.g., heatsinks). 相似文献
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We propose and experimentally demonstrate a method for temperature sensing using stimulated Brillouin scattering (SBS)-based slow light. The approach relies on temperature dependence of the Brillouin frequency shift in a fiber, hence the time delay of an input probe pulse. By measuring the delay, temperature sensing can be realized. We achieve temperature measurement in a 100 m single-mode fiber (SMF) using a cw pump. The main temperature-sensing range is ~18°C from the room temperature, limited by the SBS gain bandwidth. To apply the technique for measurement of a shorter fiber segment, a pulsed pump is used to introduce SBS slow light. Temperature sensing is achieved in a 2 m SMF with a main sensing range of around ~25°C. The scheme is easily implemented, exhibits a relatively high temperature sensitivity with a resolution better than 1.0°C, and is potentially applicable for distributed sensing. 相似文献
16.
A phase conjugating mirror combining a fused silica rod and an optical fiber is presented. This configuration combines a large diameter fused silica rod with a high laser damage threshold and an optical fiber with a low stimulated Brillouin scattering (SBS) threshold. The composed SBS generator-amplifier construction, similar to the two-cell type makes a forced SBS process, in which the Stokes beam reflected by the fiber is injected into the fused silica rod. Using this combined phase conjugating mirror in a laser-diode-pumped laser master oscillator power amplifier system, we obtained 42% SBS reflectivity at most at 100 Hz repetition rate. At the same time, the inverse beam quality parameter M(2) is reduced from 3 to 1.6, while at 400 Hz repetition rate, M(2) is reduced from 4 to 1.7. 相似文献
17.
Lee JH Tanemura T Kikuchi K Nagashima T Hasegawa T Ohara S Sugimoto N 《Optics letters》2005,30(13):1698-1700
We introduce a new figure of merit (FOM) including the input pump power limit associated with stimulated Brillouin scattering (SBS) for evaluation of the Kerr nonlinearity efficiency of optical fibers. The new FOM is expressed as gammaL(eff)P(SBS) (gamma is a nonlinearity parameter, L(eff) is effective length, and P(SBS) is the SBS threshold), while the conventional FOM is given by gammaL(eff). Using the new FOM, we perform an efficiency comparison among four types of state-of-the-art nonlinear optical fiber: a Bi2O3-based nonlinear fiber, a silica-based holey fiber, a highly nonlinear dispersion-shifted fiber, and a conventional dispersion-shifted fiber. The Bi2O3-based nonlinear fiber is found to have the best Kerr nonlinearity efficiency owing to the superior nonlinear property of the Bi2O3 glass compared with that of the silica. 相似文献
18.
In this article, the simulation results have been presented for dispersive optical communication with different electrical drivers. The length of single-mode fiber has been put in a run that is compensated by dispersion-compensated fiber. The results have been presented and it is observed that of all the electrical drivers, the NRZ rectangular is best suited for dispersive optical communication systems. For this electrical driver, the parameters like BER remain constant and low. For other drivers, the BER decreases more for RZ super-Gaussian. Similarly, the Q factor increases with runs for all types of drivers except for NRZ rectangular, for which it decreases. For all the drivers, it is clear that as the runs are varied, the eye opening penalty increases, that is, there is less eye opening as the length of single-mode fiber is increased. It is also seen that the dispersion-compensated fiber compensates for the dispersion very effectively irrespective of the type of driver. Of the two formats, return to zero (RZ) and non-return to zero (NRZ), the earlier has more eye-opening penalty as the distortion is more and is clearly visible in all the rectangular, super-Gaussian, and raised cosine RZ formats. Of the three RZ formats, it is observed that RZ rectangular has the least eye-opening penalty. The non-return to zero format has less distortion and, of the two rectangular and raised cosine, the NRZ rectangular has less eye-opening penalty. 相似文献
19.
G. B. Malykin 《Radiophysics and Quantum Electronics》2004,47(10-11):890-897
A particular example of the so-called minimum-configuration fiber ring interferometer whose loop comprises two different-length segments of a single-mode optical fiber with the same linear birefringence but different twisting is used to show that even in the case where the birefringence axes at the loop input coincide with the polarizer transmission direction, the phenomenon of polarization nonreciprocity of the fiber ring interferometer can emerge. It is shown that polarization nonreciprocity can be eliminated by the proper adjustment of the axes of a single-mode optical fiber, but the above adjustment should be changed if the waveguide temperature is changed. It is also shown that polarization nonreciprocity is a function of the light wavelength and the polarization nonreciprocity value in a fiber ring interferometer varies quasiperiodically in response to the temperature change in an optical fiber with random irregularities. 相似文献
20.
In this article, the simulation results have been presented for dispersive optical communication with different electrical drivers. The length of single-mode fiber has been put in a run that is compensated by dispersion-compensated fiber. The results have been presented and it is observed that of all the electrical drivers, the NRZ rectangular is best suited for dispersive optical communication systems. For this electrical driver, the parameters like BER remain constant and low. For other drivers, the BER decreases more for RZ super-Gaussian. Similarly, the Q factor increases with runs for all types of drivers except for NRZ rectangular, for which it decreases. For all the drivers, it is clear that as the runs are varied, the eye opening penalty increases, that is, there is less eye opening as the length of single-mode fiber is increased. It is also seen that the dispersion-compensated fiber compensates for the dispersion very effectively irrespective of the type of driver. Of the two formats, return to zero (RZ) and non-return to zero (NRZ), the earlier has more eye-opening penalty as the distortion is more and is clearly visible in all the rectangular, super-Gaussian, and raised cosine RZ formats. Of the three RZ formats, it is observed that RZ rectangular has the least eye-opening penalty. The non-return to zero format has less distortion and, of the two rectangular and raised cosine, the NRZ rectangular has less eye-opening penalty. 相似文献