共查询到19条相似文献,搜索用时 125 毫秒
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采用体式显微镜、扫描电子显微镜、拉曼光谱表征了不同氟浓度、波导结构条件下光纤预制棒锥区及光纤的表面形貌与微观结构,用光纤综合参数分析仪、自制输出激光刀头分析了大芯径掺氟包层光纤的损耗、激光传输效率.结果表明:随着氟含量的升高,氟挥发现象愈加明显,传统大芯径掺氟包层光纤表面产生的裂纹、凹坑等缺陷增多,光纤损耗略有增加,激光传输效率下降;采用下陷掺氟内包层设计有效抑制了大芯径掺氟包层光纤制备过程中的氟挥发、析晶现象,1 200nm波段光纤损耗为3.99dB/km,平形和球形光纤2μm波段的激光传输效率分别达到88.9%和88.4%,性能明显高于传统结构光纤. 相似文献
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采用改进化学汽相沉积结合溶液掺杂法制备了Yb/P/Al共掺的石英光纤预制棒,通过光纤芯层的组份和制备工艺的优化,实现了Yb3+的高浓度掺杂和均匀掺杂.预制棒芯层Yb2O3掺杂浓度达到~4wt.%,Yb3+在1 080 nm处荧光寿命为1 780μs.成功拉制出内包层截面形状为八边形的双包层光纤,纤芯直径为7.5 μm,包层吸收系数达到~5 dB/m@976 nm.利用拉制的掺镱双包层光纤开展了全光纤结构的掺镱光纤激光器性能测试实验,实现了5.15W的激光输出,斜率效率达到76%. 相似文献
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大模场面积掺镱双包层光纤研究 总被引:1,自引:1,他引:0
采用改进的化学汽相沉积工艺,沉积了光纤阻挡层和疏松层.结合溶液掺杂技术,研究了疏松层沉积温度、镱铝共掺工艺条件对掺镱浓度的影响,研究了大模场面积纤芯的制备工艺,实现了高浓度大模场面积掺镱双包层光纤的研制.测量并分析了光纤的光学性能参数及其激光特性,光纤芯径达到30 μm,纤芯摻镱浓度提高到4 000 ppm以上,芯数值孔径降至0.07,光纤的模场面积从113 μm2 提高到1 256 μm2,光纤的非线性效应阈值功率由12 W提高到大于128 W. 相似文献
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采用改进的化学气相沉积法和气相液相混合掺杂技术制备大芯径掺镱石英光纤预制棒, 以此作为有源纤芯制备了纤芯直径约90 μm的掺镱双包层光子晶体光纤, 纤芯组分为镱铝磷共掺.双包层光子晶体光纤的模场面积约1330 μm2, 纤芯数值孔径0.065,包层数值孔径0.5.首次实现了国产掺镱光子晶体光纤的高功率高效率激光输出, 1 m长的光子晶体光纤激光器实现102 W 激光输出,斜率效率76%. 相似文献
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基于小波变换和最小二乘法的光纤衰减特性分析 总被引:3,自引:1,他引:2
光纤衰减特性是光纤的一个重要性能指标 ,随着光纤通信的发展 ,迫切需要发展一种对光纤衰减特性进行自动化分析的设备。目前市场上常见的测光纤衰减特性的仪器是OTDR卡 ,但OTDR卡仅提供了各采样点处的衰减值 ,并不能对测试数据进行自动化分析。基于OTDR卡的测试数据 ,利用小波变换、最小二乘法等数学工具提出了一种光纤衰减特性自动化分析的算法。与同类产品相比 ,该算法精度较高。 相似文献
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When a silica optical fiber is used for transmitting ultraviolet (UV) light, the problems associated with the damage and transmission deterioration of silica fiber in the UV region need to be solved in the fabrication process. In this paper, an improved silica fiber fabrication process was presented to enhance UV transmission, which combined the UV pre-irradiation on high-OH concentration preform with heat treatment while drawing fiber. The impact of the structural defects and color centers was diminished greatly by the new method of fabrication. The experimental results accorded with the theoretical analysis,and transmission was improved about 0.4-0.7 dB/m for wavelength from 350 to 400 nm. 相似文献
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Laser-induced fluorescence, Raman and absorption spectroscopy are used to investigate reversible degradation of transmission in PMMA optical fibers. When exposed to 254 nm UV light, optical transmission of PMMA plastic optical fiber in 400-800 nm range shows a significant increase in attenuation for shorter wavelengths. Over a period of 10 days following UV exposure, the transmittance of the plastic fiber recovers to a significant fraction of its pre-exposure value. UV-exposed fiber exhibits strong laser-induced fluorescence with 488 nm argon-ion laser. This fluorescence spans a spectral region between 450 nm and 750 nm with a peak around 580 nm. The fluorescence intensity decreases over several days following UV exposure. Likewise, Raman is also used to investigate degradation process. Freshly UV-exposed fiber shows total absence of Raman spectrum of PMMA. Following UV exposure, recovery of Raman signal over several days is correlated to the recovery of fiber transmittance as well as the decay of laser-induced fluorescence. A widely believed plausible explanation for UV-induced increase of attenuation involves formation of different macro radicals which recombine progressively after UV is stopped. Laser-induced fluorescence over several days is reported here providing direct evidence for molecular-level deterioration and recovery of PMMA. 相似文献
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A high-birefringence linearly chirped fiber Bragg grating (FBG) is written into a polarization-maintaining photosensitive fiber by ultraviolet (UV) beam through a linearly chirped phase mask. Its performance as group velocity dispersion (GVD) and polarization mode dispersion (PMD) compensator is demonstrated in short pulse fiber optical transmission systems. 相似文献
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Laser cooling of a solid by 65K starting from room temperature 总被引:5,自引:0,他引:5
Gosnell TR 《Optics letters》1999,24(15):1041-1043
In vacuo laser cooling of a solid from 301 to 236 K has been demonstrated. The sample consists of a cladded, multimode optical fiber fabricated from the fluorozirconate glass ZBLANP; the fiber's waveguiding core is doped with 1 wt. % Yb(3+) ions. Cooling of the host glass results from anti-Stokes fluorescence of Yb(3+) following optical pumping in the long-wavelength tail of the ion's absorption spectrum (lambda=1015nm) . Measurement of the time constant for equilibration of the sample temperature is in excellent agreement with an analytic calculation of this quantity. 相似文献
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How thin can a microfiber be and still guide light? 总被引:2,自引:0,他引:2
Sumetsky M 《Optics letters》2006,31(7):870-872
For the adiabatically deformed optical fiber the intermode transmission amplitudes and loss vanish exponentially with the characteristic length of the fiber's nonuniformity. For this reason smoothly deformed optical fiber tapers can have very small losses. However, losses dramatically increase with a thinning of the microfiber down to a diameter much smaller than the radiation wavelength. The theory of nonadiabatic intermode transitions is briefly discussed and, by using this theory, the problem of the smallest diameter of a microfiber that can transmit evanescent radiation is studied. It is shown that even for an extremely high uniformity of microfiber the ability of light transmission does not leave much space for microfiber thinning: the propagating mode vanishes at a threshold value of the microfiber's diameter, that is smaller than the radiation wavelength by only an order of magnitude. 相似文献
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Cuadrado-Laborde C 《Optics letters》2007,32(19):2867-2869
A lensless dual random phase encoding technique in the temporal domain is proposed and analyzed to evaluate its potential application for secure data transmission, mainly for short-haul fiber optic links. The different signal broadening effects produced by each stage of the encoding process in both time and frequency domains are analyzed by using the Wigner distribution function to take into account the fiber's multiplexing capabilities. Thus, quasi-white noise with a well-defined bandwidth is used in the encoding process to limit the bandwidth of the encrypted signal. Numerical simulations revealed good system performance, indicating that this multiplexing encryption method could be a good alternative to other well-established techniques. 相似文献