共查询到20条相似文献,搜索用时 15 毫秒
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光纤通信技术发展的阶段性飞跃总是伴随新型光电材料和功能器件的突破.文章介绍了光纤通信系统中应用到的各种光电子器件,从光纤通信的3个环节:光发送、光接受、光放大为出发点,着重阐述了半导体激光器、光调制器、光检测器、光放大器等关键器件的基本原理、工作特性以及发展现状和趋势,并在回顾传统集成光电子器件发展的同时,展望了以新一代微纳结构光电子器件为基础的光子集成技术的发展趋势. 相似文献
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从改进斜入射斜接收式激光三角法的光路系统角度出发,提出了一种对液面反射光线采用线性光学放大的光路设计,将液面微小位移变化线性放大为光电检测器上的光点位移变化来提高液位检测分辨率。对曲面镜的线性放大原理进行了理论推导,介绍了线性放大曲面镜曲线函数表达式的数值计算方法以及计算机程序流程。仿真实验结果表明,该线性放大曲面镜可以实现线性放大功能,能够有效地提高激光三角液位检测系统的液位检测分辨率,同时可保证检测系统具有较小的非线性误差。该光路设计方法也可应用于具有位置线性放大的光学位置指示系统中。 相似文献
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基于朗伯定律重建光学三角法测位移原理公式 总被引:5,自引:0,他引:5
利用朗伯定律重构了光学三角法测位移的原理公式,与用几何光学原理建立的公式进行了比较。利用新公式对影响光学三角法漂移精度的主要误差因素进行了深入的分析,给出了实验结果,并提出了减小和校正误差的方法。 相似文献
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文章简要介绍了利用光子晶体实现微纳尺度上光调控的物理原理和工作机制,重点讨论了如何利用光子晶体的缺陷态实现微纳尺度的各种集成光电子器件,并结合文章作者所在研究组的研究工作经验,简单回顾了各种类型的集成光电子器件的工作原理、物理实现和光学特性. 相似文献
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V. Lombardo T. Marzulli C. Pappalettere P. Sforza 《Optics and Lasers in Engineering》2003,39(2):247-254
This paper reports the development of an electro-optic device for relative distance measurement. The time-of-scan triangulation technique has been used as measurement principle and a rotating mirror employed as beam deflection system. A calibration technique is needed to calculate the geometrical parameters of the system. The device has an accuracy of 100 μm, a working distance of 20 cm and a range of 10 mm. The accuracy obtained depends on the instability of the rotation speed of the mechanical scanner that affects the measurement of the scanning time. 相似文献
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Gregory Moille Sylvain Combri Laurence Morgenroth Gaëlle Lehoucq Franois Neuilly Bowen Hu Didier Decoster Alfredo de Rossi 《Laser \u0026amp; Photonics Reviews》2016,10(3):409-419
Abstract The potential of GaAs‐based photonic crystals for fast all‐optical switching in the telecom spectral range is exploited by controlling the surface recombination and, thereby, the carrier relaxation dynamics. The structure is entirely coated with a layer of aluminium oxide using atomic layer deposition. This results in a carrier lifetime of about 10 ps, as determined by spectrally resolved pump–probe measurements. We show that the nonlinear response of the resonator is optimized when it is excited with a few‐picoseconds pulse. This dynamics is perfectly captured by our model accounting for the carrier diffusion with an impulse response function. Moreover, the suppression of photo‐induced oxidation is revealed to be crucial to demonstrate all‐optical operation at GHz rates with average coupled pump power of 0.5 mW (hence 100 fJ/bit). The switching window is 12 ps wide (1/e), as resolved by homodyne pump–probe measurements. The devices respond to a sequence of closely spaced pump pulses demonstrating a gating window close to 10 ps, with a contrast as high as 7 dB.
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All-optical error-bit amplitude monitor based on NOT and AND gates in cascaded semiconductor optical amplifiers 下载免费PDF全文
This paper proposes and simulates a novel all-optical error-bit amplitude monitor based on cross-gain modulation and four-wave mixing in cascaded semiconductor optical amplifiers (SOAs), which function as logic NOT and logic AND, respectively. The proposed scheme is successfully simulated for 40 Gb/s return-to-zero (RZ) signal with different duty cycles. In the first stage, the SOA is followed by a detuning filter to accelerate the gain recovery as well as improve the extinction ratio. A clock probe signal is used to avoid the edge pulse-pairs in the output waveform. Among these RZ formats, 33% RZ format is preferred to obtain the largest eye opening. The normalized error amplitude, defined as error bit amplitude over the standard mark amplitude, has a dynamic range from 0.1 to 0.65 for all RZ formats. The simulations show small input power dynamic range because of the nonlinear gain variation in the first stage. This scheme is competent for nonreturn-to-zero format at 10Gb/s as well. 相似文献
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Reconfigurable all-optical dual-directional half-subtractor for high-speed differential phase shift keying signal based on semiconductor optical amplifiers 下载免费PDF全文
All-optical digital logic elementary circuits are the building blocks of many important computational operations in future high-speed all-optical networks and computing systems. Multifunctional and reconfigurable logic units are essential in this respect. Employing the demodulation properties of delay interferometers for input differential phase shift keying signals and the gain saturation effect in two parallel semiconductor optical amplifiers, a novel design of 40 Gbit/s reconfigurable all-optical dual-directional half-subtractor is proposed and demonstrated. All output logic results show that the scheme achieves over 11=dB extinction ratio, clear and wide open eye diagram, as well as low polarization dependence (< 1 dB), without using any additional input light beam. The scheme may provide a promising candidate for future ultrafast all-optical signal processing applications. 相似文献
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在电光、磁光调制器和传感器等光学器件的制作和使用过程中,经常会产生影响器件性能的弹光双折射.根据折射率椭球分析法,通过系统分析各晶系晶体的弹光效应,提出了若干去除光学器件中静态弹光双折射的方法.主要结论包括:对于正交晶系的双轴晶体,当光波沿着晶体任意一个主轴方向传播时,如果作用于晶体另外两个主轴方向的应力能够满足某一与晶体自身参数有关的倍数关系且不存在剪切应力,则可以去除这两个应力引起的弹光双折射;对利用所有单轴晶体,ˉ43m,432,m3m点群的立方晶体和匀质光学玻璃制作的光学器件,如果能够保持晶体沿着x1,x2轴方向的正应力相等且不存在剪切应力,或只对晶体施加x3方向的正应力,也可以避免沿着晶体主光轴x3方向传播光波的弹光双折射.上述去除弹光双折射的方法对光学器件的设计、制作和使用具有重要参考价值. 相似文献
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Investigation of PZT driven tunable optical filter nonlinearity using FBG optical fiber sensing system 总被引:2,自引:0,他引:2
K. Liu W.C. Jing G.D. Peng J.Z. Zhang D.G. Jia H.X. Zhang Y.M. Zhang 《Optics Communications》2008,281(12):3286-3290
The nonlinearity of a piezo-electrical transducer (PZT) driven tunable optical filter (TOF) is investigated and evaluated using FBG optical fiber sensing system including a broadband optical source and a tunable laser (TL) with a group of fiber Bragg gratings (FBGs). Polynomial fit is adopted to model the nonlinearity. Under three-order polynomial fit, the random error in wavelength measurement using this TOF and a reference FBG is minimized to be below 20 pm. At the same time, the absolute error in wavelength measurement is kept below 0.25 nm. Under four-order or higher polynomial fit, a sharp increase of the random measurement error is observed. This research reveals the possibility of using PZT driven TOFs in optical spectroscopy where high resolution, high-accuracy, and fast time-response is required. 相似文献
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光导纤维在载荷测量及角位移测量中的应用 总被引:2,自引:0,他引:2
介绍了力学量中载荷和角位移的测量传感器。其方法是利用光导纤维作为传感器主要元件,被测载荷使弹性元件变形,使光纤端面间光的耦合效率发生变化,通过测量光通量的变化而测知载何和角位移的大小。在载荷测量中特殊布置光纤的位置,通过电路对信号的差分处理能达到提高传感器线性度的目的。最后的传感器输出结果其非线性大为减小。角位移的测试中,这种角位移光纤传感器灵敏度高,分辨率小,适合于扭转试件的微小角位移测量。这类光纤传感器用于力学量测试可弥补一些传统测量方法的不足。 相似文献
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Starting from optical nihility media (ONM), we design several intriguing devices with transformation optics method in two dimensions, such as a wave splitter, a concave lens, a field rotator, a concentrator, and an invisibility cloak. Though the extreme anisotropic property of ONM hinders the fabrication of these devices. We demonstrate that those devices could be effectively realized by simplified materials with Fabry–Pérot resonances (FPs) at discrete frequencies. Moreover, we propose a reduced version of simplified materials with FPs to construct a concentrator and a rotator, which is feasible in experimental fabrications. The simulations of total scattering cross-sections confirm their functionalities. 相似文献
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Darren D. Hudson Eric C. Mägi Alexander C. JudgeStephen A. Dekker Benjamin J. Eggleton 《Optics Communications》2012,285(23):4660-4669
In this review we consider the basic elements of tapering chalcogenide optical fibers for the generation of extreme spectral broadening through supercontinuum generation. Creating tapered nanofiber devices in chalcogenide fiber, which has an intrinsic nonlinearity that is two orders of magnitude higher than silica, has resulted in the demonstration of octave-spanning spectra using record low power. We first present a brief theoretical understanding of the tapering process that follows from the basic principle of mass conservation, and a geometric construction tool for the visualization of the shape of tapered fibers. This is followed by a theoretical treatment of dispersion engineering and supercontinuum generation in a chalcogenide nanofiber. In the final section, we cover the experimental implementation of the chalcogenide nanofiber and demonstrate an octave-spanning spectrum created with 150 W of peak power. 相似文献
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设计了一个大扫描视场的折衍混合红外共形光学系统,共形成像系统工作波段为3.7~4.8 m,相对孔径为1/2,焦距为120 mm,扫描视场为40。由于共形光学系统具有大偏心、大倾斜光学特性,像差校正难度较大,设计中采用固定校正镜和折衍混合混合结构校正了共形光学元件的像差,引入了非球面和衍射面有效消除了各个扫描视场的像差。设计结果表明:光学系统光阑与探测器冷光阑重合,满足100%冷光阑效率。在40扫描视场范围内,共形光学系统的光学传递函数曲线接近衍射极限,成像良好。 相似文献
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Anisotropic optical feedback of single frequency intra-cavity He--Ne laser 总被引:1,自引:0,他引:1 下载免费PDF全文
This paper presents the anisotropic optical feedback of a single
frequency intra-cavity He--Ne laser. A novel phenomenon was
discovered that the laser output an elliptical polarized frequency
instead of the initial linear polarized one. Two intensities with a
phase difference were detected, both of which were modulated in the
form of cosine wave and a fringe shift corresponds to a λ/2
movement of the feedback mirror. The phase difference can be
continuously modulated by the wave plate in the external cavity.
Frequency stabilization was used to stabilize the laser frequency so
as to enlarge the measuring range and improve the measurement
precision. This anisotropic optical feedback system offers a
potential displacement measurement technology with the function of
subdivision of λ/2 and in-time direction judgment.
The three-mirror Fabry--Perot cavity model is used to present the
experimental results. Given the lack of need of lasing adjustment,
this full intra-cavity laser can significantly improve the
simplicity and stability of the optical feedback system. 相似文献
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A two-beam laser triangulation method has been proposed to measure the position of a moving object. The method uses two parallel laser beams to judge the moving direction of an object, allowing us to track it and measure its positions. An uncertainty of 0.2 mm for a measurement range of 50 mm has been obtained. This tracking measurement capability is useful in the calibration of the position of a moving robot arm. 相似文献