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1.
设计了一种基于LiNbO_3的长周期波导光栅可调谐耦合器.该耦合器利用长周期光栅的独有特性将输入波导的导模经包层模耦合至输出波导导模.由于LiNbO_3的电光效应,波导光栅芯层与包层的有效折射率随外加电压变化,从而耦合器的谐振波长及耦合效率可由外加电压调谐.分析了光栅周期与耦合器的长度对耦合器带宽和耦合效率调谐范围的影响,以及波导尺寸对谐振波长调谐灵敏度的影响.结果表明光栅周期越短,耦合器长度越长,则耦合器的带宽越窄,耦合效率调谐范围也越大.此外,谐振波长调谐灵敏度随波导宽度的增加而减小,而波导厚度对谐振波长调谐灵敏度的影响可以忽略.对光栅周期为94μm、长度为3.52cm的耦合器进行仿真,结果表明,谐振波长灵敏度为26.2pm/V,3dB带宽可达4.5nm,当外加电压从0变化到200V时,谐振波长变化5.24nm,耦合效率可在1到0.15之间进行调谐. 相似文献
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研究了一种基于线性啁啾光纤布拉格光栅(LCFBG)和热光相移技术的可编程带宽波长独立可调光纤光栅滤波器,透射峰数目、带宽、中心波长及波长间隔独立可调。由于热光效应,对LCFBG局部区域进行加热便可在加热处引入相移,使LCFBG透射禁带上产生透射峰。采用可编程的热打印头作为数字化加热单元,精确加热光纤光栅的特定位置,通过控制加热区域的数目和加热区域的间隔来分别确定透射波长的数目和透射波长的间隔;通过改变LCFBG被加热区域的宽度,实现可变带宽滤波。此可编程带宽波长独立可调光纤光栅滤波器的透射峰带宽调谐范围为0.07~1.55nm,透射峰中心波长调谐范围为1547.44~1558.64nm,两透射峰间距最小为0.95nm。 相似文献
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提出了一种基于Sagnac环干涉结构的光梳状滤波器。该结构利用保偏光纤双折射效应产生梳状滤波响应,通过控制Sagnac环内相位调制器的驱动信号实现光学滤波器陷波深度与滤波波长的独立调谐。利用Jones矩阵对所提出的Sagnac环光滤波器的滤波响应函数进行研究,通过分析得到光滤波器的陷波深度和滤波波长分别与射频信号和直流偏压之间的关系。在此基础上构建实验链路,验证了系统的理论分析,实现了光滤波器陷波深度在0dB~30dB范围内的灵活控制;通过设置直流偏压在0~12V范围内变化,实现了光滤波器滤波波长在一个自由光谱范围(0.5nm)内的连续可调,波长调谐效率为0.043nm/V。 相似文献
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基于光栅层控制光波传播耦合波方程,设计了能够实现共振波长可调谐的亚波长光栅导模共振滤波器.通过调谐空气层的厚度,滤波器可以实现波长75nm的调谐,线宽均小于或等于1nm.将共振波长可调谐滤波器与中心波长为1.55μm的垂直腔面发射激光器(VCSEL)集成,形成了激射波长可调谐VCSEL.研究发现激射波长调谐范围与共振波长可调谐滤波器相同,而且在相同空气层厚度下,激射波长可调谐VCSEL的激射波长和共振波长可调谐滤波器的共振波长相同.该VCSEL不仅可以选择激射波长还可对输出横向模式进行选择. 相似文献
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为解决850 nm波长VCSEL表面的GaAs/空气材料的高对比亚波长光栅( HCGs)稳定性差的问题,设计了基于Si/SiO2材料的高对比亚波长光栅。研究了850 nm波长高稳定、高反射率(>99.5%)的高对比亚波长矩形光栅参数的变化对反射率的影响。利用有限元分析软件计算了Si/SiO2高对比亚波长光栅的高度、填充因子、周期、刻蚀深度及光栅倾角等各个参数的变化对850 nm的反射率影响。计算结果表明:当波长为850 nm的TE光从SiO2正入射到矩形HCGs且只有在光栅的倾角大于88°的小范围内变化时,HCGs的反射率才大于0.995,而光栅的其他参数对HCGs反射率的影响可以忽略不计。 相似文献
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Zhiping Wang Benli YuShenglai Zhen Xuqiang WuJun Zhu Zhigang Cao 《Superlattices and Microstructures》2012
We investigated the optical bistability and multistability in an Er3+-doped ZrF4–BaF2–LaF3–AlF3–NaF optical fiber inside an optical ring cavity. It is found that the optical bistability and multistability can be easily controlled via adjusting properly the parameters of the corresponding system. Our scheme may provide some new possibilities for technological applications in optoelectronics and optical-fiber communication. 相似文献
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Haroldo T. Hattori Vitor M. Schneider Osni Lisba Rogrio M. Cazo 《Optics & Laser Technology》2001,33(5)
Raman and Brillouin effects have found special applications in distributed sensing for smart materials and structures. In these sensors, the fiber acts as a distributed sensor, sensing strain and temperature over a range of tens of kilometers and, at the same time, carries this information to the installation that will process them. In order to optimize the fiber to operate under the Brillouin and Raman regimes, a special elliptical fiber with small effective area has been designed, which will allow these sensors to cover longer distances and/or employ lower power lasers. 相似文献
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A novel arithmetic unit is proposed consisting of a pipelined optical ripple carry adder that adds two words with bits multiplexed by different wavelengths on a single fiber. The addition result is returned to a fiber bus in the same format as the incoming words. The corresponding operand bit pairs are split off the fiber using wavelength division demultiplexers. Full adders compute the sum for each bit pair and the carry from the next lower significant bit pair. The full adder uses couplers and NOT, NOR and novel XOR logic gates constructed using semiconductor optical amplifiers for gain and wavelength shifting. 相似文献
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We show that high extinction ratio (>20 dB) modal interference in a two-mode dispersion compensating fiber can be utilized to build a compact, easy-to-fabricate tunable all-fiber optical comb filter. Wavelength tunability over the full free spectral range of the comb filter is demonstrated with an electrical power of 115mW using an on-fiber thin film micro-heater deposited directly on the fiber. In another configuration, the comb filter is used as a temperature sensor with dynamic range of >300 °C and sensitivity of <0.1 °C. The temperature sensor is capable of measuring a temperature as high as 500 °C. 相似文献
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Experimental measurement and analysis of the optical trapping force acting on a yeast cell with a lensed optical fiber probe 总被引:1,自引:0,他引:1
Based on an optical trapping system with a single-lensed fiber probe inserted at an angle, the sub-picoNewton trapping force acting on a yeast cell as a function of the displacement is measured experimentally by the static and dynamic methods, respectively, whose measurement processes are presented in detail. The measured maximum trapping efficiency is 0.07 in our experiment, which is an order of magnitude lower than that of the optical tweezers. The characteristics of the trapping force in the various horizontal directions are discussed. Finally, the analysis of the measurement error shows the factors and their magnitude which cause error, and offers a way to reduce the error in future. 相似文献
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Jong-Moo Lee Yong-Soon Baek Kwang-Ryong Oh Hyung-Jong Lee Yong-Seok Kim 《Optics Communications》2007,270(2):189-194
We investigate on the variation of loss and temperature dependence of a polymeric arrayed waveguide grating (AWG) depending on its substrate, by fabricating 16-channel polymeric AWGs with various substrate conditions. Insertion loss for a polymeric AWG on a silicon substrate is measured as low as 3.1 dB. The temperature-dependent wavelength shift for a polymeric AWG detached from the substrate is maintained within 0.1 nm from 20 to 80 °C. But we observe a degradation of insertion loss and a little instability in wavelength characteristics both for the detached polymeric AWG and for a polymeric AWG on a polymer substrate. We investigate on those optical properties of the polymeric AWGs based on measured thermal expansion properties of the polymers. 相似文献
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Haixuan Huang Jing Yang Xiangdong Gong Lili Wan Kai Wang Yeyong Zheng Xuan Han 《Optics Communications》2009,282(21):4198-4202
Based on the Left Perfect Shuffle (LPS) optical communication network constructed by cascade multi-stage LPS interconnection, using Looping algorithm, any arbitrary sequence of the input signals can be realized. However, instead of obtaining the simultaneous state codes of the same level node switches through mathematical analytical expressions directly, only routing tags of each channel can be obtained through mathematical analytical expressions so as to draw out topological chart of the network to obtain the state codes implied in the chart. Thus, the states of the switches cannot be directly programmed and controlled by computer in practical application. In this paper, based on the Looping algorithm, a method of stage code matrixes is presented to resolve this problem. By using the method, the simultaneous state codes of the same level’s four node switches can be directly obtained, which is convenient for the computer to provide controlled signals needed to finish the permutation for each node switch. The method of stage code matrixes provides further theoretical basis for the realization of optical switching by integration of Perfect Shuffle and high-speed optical switches. 相似文献
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The absorptive peaks of the H2O-groups were observed in the infrared absorption spectra in the vicinity of 3480 cm−1 in LiNbO3 and LiTaO3, and 3580 cm−1 in α-quartz. The absorptions of these lines were found to depend on the vibration direction of the polarized incident light, showing the dichroic property in these crystals. The absorption of the ordinary ray waves is much larger than that for the E-ray waves in the crystals. This observation indicates that the direction of the bond vibrations for the H2O-groups is perpendicular to the optic axis of crystals. The dichroic property of the H2O-groups may serve as the tracer to study the local electric field in piezoelectric crystals. 相似文献
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Anjan Biswas 《Fiber and Integrated Optics》2013,32(6):571-579
The variational principle is employed to obtain the evolution of the parameters of Gaussian and super-Gaussian chirped solitons that propagates through multiple-core nonlinear optical fiber arrays. This is governed by the dispersion-managed nonlinear Schrodinger's equation with strong dispersion management in the presence of linear coupling between the adjacent cores. The results are valid for any configuration of the cores. 相似文献
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此文研究了三种不同分子结构的聚苯胺(本征态聚苯胺,间位聚苯胺和掺入有机玻璃的掺杂态聚苯胺)的飞秒非线性光学响应过程。用飞秒时间分辨吸收光谱技术测量了三种样品的激子和极化子的光激发和弛豫过程。从一个三能级模型出发,分析了上述过程的来源。最后讨论了存在于聚苯胺中的这种超快驰豫过程在光学双稳器件中的应用 相似文献