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An Integrative Biosensor Based on Contra-Directional Coupling Two-dimensional Photonic Crystal Waveguides 下载免费PDF全文
We propose an integrative biochemical sensor utilizing the dip in the transmission spectrum of a normal singleline defect photonic crystal (PC) waveguide, which has a eontra-directional coupling with another PC waveguide. When the air holes in the PC slab are filled with a liquid analyte with different refractive indices, the dip has a wavelength shift. By detecting the output power variation at a certain fixed wavelength, a sensitivity of 1.2 × 10^-4 is feasible. This structure is easy for integration due to its plane waveguide structure and omissible pump source. In addition, high signal to noise ratio can be expected because signal transmits via a normal single-line defect PC waveguide instead of the PC hole area or analyte. 相似文献
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Two-dimensional photonic crystal slab waveguides on SOI wafer are designed and fabricated. Photonic band gap, band gap guided mode, and index guided mode are observed by measuring the transmission spectra. The experimental results are in good agreement with the theoretical ones. 相似文献
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Er^3+/Yb^3+掺杂全光纤环形激光器 总被引:1,自引:1,他引:0
本文报道利用Er~(3+)/Yb~(3+)掺杂单模光纤首次研制成功的环形谐振腔结构的可调谐(调谐范围宽于70nm)全光纤激光器的设计原理及其实验结果. 相似文献
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用于级连EDFA增益谱平坦的滤波器透过谱设计的迭代算法 总被引:2,自引:0,他引:2
针对在两段掺铒光纤中插入滤波器实现宽带 (35nm)增益平坦的滤波器透过谱的设计问题 ,提出了一种新的迭代算法。其原理是利用放大器的均匀展宽特性和级连放大器自动增益补偿的特性。在每次迭代中 ,都取要求带宽内增益 (分贝数 )的平均值为参考轴 ,在增益比该轴高的波长范围内再附加一与增益谱反对称的损耗谱。而增益低于参考值的波长处则会得到自动的增益补偿。模拟计算结果表明 ,用该方法得到的滤波谱能使放大器的增益平坦在原放大器可能得到的最高增益水平 ,同时因滤波器的引入带来的噪声特性恶化也最小。 相似文献
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空心Bragg光纤可广泛用于气体传感, 但要求它的传输通带处于中红外波段, 以便与待测气体的基频吸收峰匹配. 本文提出了空心Bragg光纤传输通带的一种设计方法与波长控制工艺, 可以实现传输通带在2.5-12 μ m内任意波长的空心Bragg光纤的制备. 实验制备出一阶传输通带分别在10.6 μ m和 3.3 μ m的光纤样品, 利用截断法测量出其一阶传输通带损耗分别为5.9 dB/m和8.8 dB/m. 利用在传输通带在3.3 μ m的样品中注入和排出甲烷/氮气混合气体, 观察到了光纤样品透射谱随注入气体浓度的变化, 并用指数稀释法初步测量了该系统的浓度探测极限约为26 ppm, 验证了该光纤应用于气体传感的可行性. 相似文献
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Considering spectrum tilt due to signal-to-signal Raman scattering (SSRS) in backward distributed fiber Raman amplifiers (B-DFRA), an inverse tilted on-off gain profile is adopted to achieve flat net gain. A simple approximate linear relationship of pump power at each wavelength versus on-off gain level and tilt was derived numerically and experimentally so that a novel control method was established. Since there are only 3 pre-determinable constants required for individual pump wave, it is easy to be realized. As an example, maximum errors less than 0.2 and 0.4 dB respectively for average gain and gain tilt were achieved over C+L band in 100-km back-pumped standard single-mode fiber (SMF) experimentally. 相似文献
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