共查询到20条相似文献,搜索用时 685 毫秒
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A new multiple-taps and flat microwave photonic filter, which is composed of fiber Bragg grating, M-Z modulator and erbium-doped fiber, is put forward. The flat band-pass or flat band-stop response can be realized by adjusting the coupler's factor and the reflectivity of the fiber Bragg grating or the gain of the erbium-doped fiber. The free spectral range of the filter can be tuned by controlling the length of the erbium-doped fiber. The potential and feasibility of the proposed filtering structures have been demonstrated by simulation. 相似文献
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ZHANGXiao-guang YULi YANGBo-jun LIUYu-min YUZhong-yuan 《半导体光子学与技术》2003,9(4):209-211,225
A novel tunable chirped fiber Bragg grating technology is proposed and simulated numerically by Matlab. If we adhere a uniform fiber grating with super magnetostrictive film and expose them in a non--uniform magnetic field, the period of the grating can be changed with the strain imposed on it by the magnetostrictive effect . The chirped characteristics can be tuned by changing the magnetic filed which is very flexible indesigning. 相似文献
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KANG Yun YE Cheng-chun LUO Zheng-qian SI Miao-ling 《光电子快报》2007,3(2):112-114
The characteristics of chirped and phase-shifted fiber Bragg gratings have been investigated by the use of transfer matrix formulation. While the characteristics of a chirped and phase-shifted fiber Bragg grating are the same as those of non- chirped one in some important aspects, both the reflection and transmission windows of a chirped and phase-shifted fiber Bragg grating can be broadened in a wide range. Therefore, chirped and phase-shifted fiber Bragg gratings will have applications in WDM or DWDM optical communication systems. The work in this paper can be used to design the new devices based on chirped and phase-shifted fiber Bragg gratings. 相似文献
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SANG Xin-zhu YU Chong-xiu YAN Bin-bin MA Jian-xin LU Nai-guang 《半导体光子学与技术》2006,12(4):238-241
Chirped fiber Bragg gratings have found many applications in optical communication and sensing systems. High quality filters based on chirped fiber Bragg gratings with reflection bandwidth of 2.6 and 32nm and high reflectivity are demonstrated experimentally with 2 and 4cm long phase masks, respectively. These filters with flat reflection band and high reflectivity are achieved by writing type IIA chirped Bragg gratings. 相似文献
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A novel fiber Bragg grating (FBG) current sensor with temperature compensation has been proposed. The fiber Bragg grating is glued on the surface of an isosceles triangle cantilever beam, which has a step thickness along the beam axis. Due to the electromagnetic force created by a solenoid and a permanent magnet mounted on the top of the beam, a step strain is applied on the fiber Bragg grating. The change of the electric current in the solenoid makes the spectrum of the fiber Bragg grating split. By monitoring the shift difference of the two split center wavelengths, which is related to the electric current in the solenoid, a current sensor with temperature compensation is obtained. The test range of 0-400 mA is achieved. The experimental results also show that the relationship between the shift difference of the two split center wavelengths of the FBG and the electric current has a linearity of 0.9937, and the sensitivity is about 2.64 nm/A; the test results are independent of the temoerature, so the cross sensitive problem is solved. 相似文献
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A transmission filter composed of a Sagnac loop and a fiber Bragg grating is studied in detail.It is found that the transmission spectrum of this filter is the splitting of the reflection spectrum of the fiber Bragg gratings.The filter can behave as a multiple-passband filter when the fiber Bragg grating is strong and as a single-band filter when the fiber Bragg grating is weak.Very narrow transmission filters can be obtained in this way. 相似文献
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LIUYu-min YUZhong-yuan YANGHong-bo YANGBo-jun YULi ZHANGXiao-guang 《半导体光子学与技术》2004,10(4):225-227,232
The characteristics of special apodized fiber Bragg grating (FBG) in flat--top pass--band as reflectivity filter are presented. This special apodized FBG was designed by the particle swarm optimization algorithm. Compared with conventional apodized FBG, the special apodized FBG presented was more robust in the flat—top pass——band characteristic even if the strength of grating is very week. This technology is very interesting in designing the filter for wavelength division multiplexing system. 相似文献
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A novel dual-wavelength fiber laser with asymmetric fiber Bragg grating(FBG) Fabry-Perot(FP) cavity is proposed and experimentally demonstrated. A couple of uniform FBGs are used as the cavity mirrors, and the third FBG is used as intracavity wavelength selector by changing its operation temperature. Experimental results show that by adjusting the operation temperature of the intracavity wavelength selector, a tunable dual-wavelength laser emission can be achieved. The results demonstrate the new concept of dual-wavelength lasing with asymmetric FBG FP resonator and its technical feasibility. 相似文献
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The shift mechanism of Bragg wavelength with stress variation for a fiber grating is investigated in detail.The influence of strain change on reflection and bandpass is theoretically analyzed.By applying stress, the dynamic single/dual-channel filter with tunable fiber Bragg gratings is achieved. 相似文献
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FUHai-wei FUJun-mei QIAOXue-guang 《半导体光子学与技术》2004,10(4):278-281
A kind of fiber Bragg grating pressure sensor based on corrugated diaphragm is proposed. The relationship between the central wavelength of reflective wave of FBG and pressure is given, and the expression of the pressure sensitivity coefficient is also given. Within the range from 0 MPa to 0.3 MPa, the experimental pressure sensitivity is 7. 83 nm/MPa, which is 2 610 times than that of the bare fiber grating. The experimental results agree with the theoretical analysis. It is indicated that the expected pressure sensitivity of the sensor can be obtained by optimizing the size and mechanical parameters of the corrugated diaphragm. 相似文献
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全光纤转动拉曼激光雷达的光纤光栅分光技术研究? 总被引:1,自引:1,他引:0
设计了一款由可见光波段的光纤布喇格光栅和光纤耦合器构建的全光纤转动拉曼激光雷达分光系统。利用相位掩模板侧向成功刻写530 nm波段光纤布喇格光栅,并初步测试其透射谱和反射谱性能。为提高光纤光栅中心波长与大气氮气分子转动拉曼谱线的匹配特性,利用悬臂梁设计高调谐灵敏度的调谐系统。实验结果表明,成功研制的可见光波段光纤布喇格光栅其反射率约为95%,带宽约为0.3 nm,应力调谐系统可实现± 0.6 nm范围18 pm/r 的波长调谐。 相似文献
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基于SPSS软件的取样光栅传感特性分析 总被引:1,自引:1,他引:0
基于耦合模理论,采用传输矩阵法分析了取样光栅反射谱,取样光纤光栅在受到外界环境应变和温度影响时,其反射光谱的反射率和波长会发生变化。通过测量反射光谱的反射率变化和波长漂移,就能够实现用单根的取样光纤光栅同时测量应变和温度。通过仿真实验获得了取样光纤光栅的应变和温度传感数据。利用SPSS13.0统计学软件计算出了取样光栅反射率和波长与温度、应变变化的函数关系式,得到系数矩阵中A,B,C,D分别为-0.00033/ε,-0.00011/℃,-0.00055nm/ε,0.013nm/℃。应变测量范围为0~180 相似文献
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Reflectivity-tunable fiber Bragg grating reflectors 总被引:2,自引:0,他引:2
Ding-Wei Huang Wen-Fung Liu Cheng-Wen Wu Yang C.C. 《Photonics Technology Letters, IEEE》2000,12(2):176-178
We report a novel device that modulates the Bragg reflectivity of a fiber grating by exciting the transverse vibration of the fiber through an acoustic wave. The excitation of the transverse vibration, leading to fiber microbending, induces the coupling of the fiber core mode into cladding modes. This leads to the reduction of core-mode power and hence that of Bragg reflection. This mechanism provides us a means to control the reflectivity after a fiber Bragg grating is fabricated. The numerical results based on a simple micro-bending model agree well in trend with the experimental data 相似文献
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本文将全面分析Chirped Bragg光纤光栅的色散特性,并对色散特性作一定性分析,利用耦合模方程导出ChirpedBragg光栅的反射率方程,从而推导出Chirped Bragg光纤光栅的色散计算公式,然后,引入微波领域的“品质因素”概念,从而量化了色散补偿器的补偿能力。 相似文献
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利用窄带光纤光栅简单而有效地实现了RoF系统中单边带调制,克服长距离传输时的色散损耗.分析了RoF系统中双边带调制对系统带来的影响,以及单边带滤波对窄带光纤光栅反射光谱和反射率的要求.研究了采用基于窄带光纤光栅的单边带调制后,对不同调制方式、不同调制速率、不同传输距离的RoF传输系统性能的改善情况.实验研究表明,光纤光栅单边带调制在以16QAM调制的15GHz RoF系统中传输25km后,信噪比与双边带调制相比可提高约4dB. 相似文献
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光纤耦合器上写入光栅制作滤波器的实验研究 总被引:4,自引:2,他引:2
全光纤波长选择滤波器是光纤通信系统中的重要器件,其中将光栅写在光纤耦合器的耦合区上构成的波长选择滤波器结构紧凑、插入损耗小、费用低。报道了采用波长为244nm的紫外光在由康宁SMF-28光纤熔融拉锥制作的2×23dB耦合器上写入光栅的实验,在耦合器熔锥区的适当位置写入一定长度的布拉格光栅,可以实现全光纤多端口波长选择滤波器。实验中获得了最大反射率约为20dB,线宽大于1nm的滤波器,并采用超模理论对实验结果进行了定性分析。要获得高的下载效率,必须仔细控制写入光栅的位置和平移台的移动速度。 相似文献