全光纤转动拉曼激光雷达的光纤光栅分光技术研究?

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。     

带状光纤多波长阵列光栅刻写工艺研究

为了实现一次性在八芯带纤上不同波长阵列光纤光栅刻写,采用专门设计的带纤夹具夹持光纤,使用电控位移平台对带状光纤整体施加拉力,利用相位掩膜工艺对光纤逐根曝光,采用扫描写入的方法进行汉明切趾,仅用单一相位模板就实现了八芯带纤上不同波长阵列布喇格光纤光栅刻写。刻栅过程由电脑编程控制,中心波长、波长间隔以及切趾方式可以灵活调整。结果表明,获得的光栅其3dB带宽为0.2nm、波长间隔为0.5nm、波长偏差小于50pm、反射率达到80%~85%。此种带状光纤多波长阵列光栅刻写工艺是完全可行的。     

利用动态相位掩膜板法制作光纤光栅

在相位掩膜板法光纤Bragg光栅(FBG)制作系统中,通过高精度陶瓷压电(PZT)促动器对相位掩膜板进行运动控制,实现对光栅折射率交流调制量和相位的任意调制,从而实现相移、切趾和啁啾等FBG的制作,从而提高FBG制作工艺的灵活性。     

Self-compensated dispersion tuning of a mode-locked fiber laserusing a linearly chirped fiber grating

A new approach of self-compensated dispersion tuning is developed to generate wavelength-tunable pulses from a fiber laser. A linearly chirped fiber grating is used in conjunction with a pair of optical circulators and modulators in the cavity. The wavelength has been electrically tuned while maintaining a constant operating frequency of 1 GHz. The laser exhibits a linear tuning relation with respect to the delay time between the electrical control signals. Three chirped gratings providing dispersions of 1446, 50, and 10 ps/nm are used respectively in the experiment and the results are compared. The highest tuning range is about 1 nm and is limited by the chirped bandwidth of the gratings     

基于莫尔光纤光栅的带通滤波器

通过改变写入条件,控制两次曝光量、光纤拉伸大小和起始位相差等参数,可以调整π相移点的位置,制作出符合要求的相移光纤光栅.用同一块均匀相位板在普通的SMF-28单模光纤上制作出了3 dB带通宽度分别为0.01和0.5 nm的带通滤波器,符合理论模拟的计算结果.利用啁啾量为10 nm/cm,长度为1 cm的啁啾相位掩模板制作了7信道的带通滤波器.     

基于相位掩模板的常规光纤制备弱反射光栅

为了探索采用常规单模光纤制备弱反射光纤光栅的可行性,以降低材料成本和传输损耗,基于相位掩模板法,在常规单模光纤上刻制弱反射光纤布喇格光栅(WFBG),并进行了实验验证.建立相位掩模板刻栅系统光场统一方程,分析光场分布对光纤布喇格光栅(FBG)中心波长和反射率的影响;采用传输矩阵法分析相位掩模板长度、平均折射率变化对FB...     

基于磁调谐光纤Bragg光栅的全光纤型多路分/插复用器

提出了一种新型的用作多信道切换的光分／插复用器,它由多个可调谐光纤Ｂｒａｇｇ光栅、一对光纤环行器、ＷＤＭ复用器和解复用器构成。讨论了该分／插复用器的结构、性能和特点。利用磁极间磁场力使光纤光栅产生显著的波称偏移。用可编程磁极来调控光栅的波长偏移。其信道波长调谐速度快,装置无需外加能源即可保护信道波长的偏移。     

随机相位误差对光纤光栅的影响

利用耦合波理论,分析了由于相位掩模板的接缝误差及光纤光栅写入过程中引入的相位误差对光纤光栅特性的影响.通过数值模拟,得到了随机相位误差对不同啁啾量的线性啁啾光纤光栅的影响.讨论了在通信系统中用光纤光栅进行色散补偿时,应该如何选取光纤光栅的啁啾量.     

Modified Talbot interferometer for fabrication of fiber-opticgrating filter over a wide range of Bragg wavelength and bandwidth usinga single phase mask

A technique involving a compact apparatus that combines the phase mask and two-beam interferometric techniques is presented. It involves the use of a phase mask to diffract the ultraviolet (UV) beam and a cylindrical lens combined with a pair of mirrors to produce two symmetric virtual line sources of UV light. Bragg wavelength and bandwidth of the fiber gratings can be controlled with a simple translation of the fiber and/or the phase mask. Using a 40-mw continuous-wave frequency-doubled argon-ion laser at 244 mm and a single phase mask, a series of chirped fiber gratings with the Bragg wavelength in a wide range around 600 nm and 1300 nm are fabricated in hydrogen-loaded ordinary fibers     

A four-element fiber grating sensor array with phase-sensitivedetection

A four-element, time-division multiplexed, fiber grating sensor array operating between the wavelengths of 1280 and 1310 nm was constructed and tested. The array consists of a 1300-nm edge-emitting LED that illuminates four gratings spaced five meters apart. Each grating in the array reflects a spectrally narrow-band (0.3-0.5 mn) wavelength region. Measurand-induced changes in the grating period change the wavelength of the light reflected by each grating. The wavelength shifts are converted to phase changes by routing the reflected signal through a nearly path balanced fiber Mach Zehnder interferometer. The minimum detectable strain was measured to be as low as 2 nanostrain/√(Hz) for frequencies greater than 10 Hz     

波长可切换窄线宽单频掺镱光纤激光器（特邀）

基于光纤环形激光器,设计出由三端口环形器、偏振控制器、未泵浦保偏掺镱光纤和光纤布拉格光栅组成的滤波器件作为高精度滤波器对谐振腔内的模式个数进行抑制,通过调谐偏振控制器,在保偏掺镱光纤内形成的梳状光谱和动态光栅,实现了窄线宽、单、双波长可切换单频掺镱光纤激光器。单波长运行时,在1064.37 nm处测得激光器输出线宽346 Hz,光信噪比大于50 dB,30 min内该激光器波长及功率的不稳定性均在0.01 nm和0.2 dB范围内。通过调节偏振控制器,单波长和双波长可以实现互相切换,双波长分别位于1064.156 nm和1065.236 nm。该技术为超窄线宽激光器的双波长输出提供了新的途径。     

金属化光纤光栅的温度调谐

报道了对光纤光栅进行金属化 ,利用金属层的电热效应对光纤光栅进行温度调谐的方法。这种调谐方法具有结构简单、使用方便、体积小、调谐速度快、易于与电子线路集成等优点。当调谐电流从 0mA增加到 180mA时 ,光纤光栅的布拉格波长从 15 5 3 14nm增加到了 15 5 5 4 8nm ,移动了 2 34nm。调谐上升时间约为 2 0ms。对实验结果作了分析讨论     

Large Deformation In-Fiber Polymer Optical Fiber Sensor

We demonstrate the measurement of the phase shift in a polymethylmethacrylate single-mode optical fiber interferometer, operating at a wavelength of 632.8 nm, up to 15.8% nominal strain in the fiber. The phase-displacement sensitivity is measured to be 1.39 x10 radldrm^-1 for this strain range. This strain range is well beyond the yield strain of the polymer fiber and that previously measured for polymer Bragg gratings and silica optical fiber sensors.     

Occurrence of Features of Fiber Bragg Grating Spectra Having a Wavelength Corresponding to the Phase Mask Periodicity

The use of a phase mask with 536 nm uniform pitch allowed the fabrication of a fiber Bragg grating for use at a Bragg wavelength of 785 nm. Reflection and transmission features at 1552 nm, twice the Bragg wavelength, associated with the phase mask periodicity were observed. However, when phase mask orders other than ＋1 were absent during fabrication the features at 1552 nm were not evident.     

超短光纤光栅刻写及其切趾方法研究

常用的光纤光栅的栅区长度为厘米量级,影响了其在非均匀物理场测量的应用.将光栅的栅区长度压缩到百微米以下,可以解决非均匀场的测量和光谱变形的问题.本文通过设置狭缝光阑以及调节掩模板与光纤之间的距离,实现了光栅有效长度的大幅度缩短,刻写出长度分别为0.1 mm、0.2 mm、0.5 mm,3 dB带宽为7.9 nm、4.2...     

光纤光栅电磁调谐技术的研究

提出了一种实用可行的控制光纤光栅波长的电磁调谐技术。实验表明 ,此调谐方法在 30 0mA电流下可达到 1 38nm的调谐范围 ,且具有较好的恢复性。可以应用于可动态配置全光分 /插复用器OADM系统中 ,也可用来对光纤光栅外腔激光器进行调谐和波长锁定 ,并可用于波长调制型传感器。     

内置光纤光栅的主动锁模光纤环形激光器输出光脉冲波长的电切换

介绍了内置光纤光栅的主动锁模光纤环形激光器输出光脉冲波长电切换的工作原理和实验结果。同一个光纤环形激光器输出的由光纤光栅布喇格波长决定的两个不同波长的光脉冲可以每秒十万次的速度切换。     

Inline quantum-well waveguide photodetectors for the measurement ofwavelength shifts

A two-segment GaAs-InGaP-InGaAs p-i-n quantum-well waveguide photodiode has been fabricated and demonstrated to function as a sensitive wavelength monitor. The ratio of the two segments' photocurrents varies linearly with wavelength in a region near the absorption band edge. A wavelength sensitivity on the order of 1 pm was measured for input optical power levels above 30 μW and signal averaging times of 0.2 s. An operating range from 980 to 1020 nm was achieved using electroabsorption tuning of the band edge. The intended application for this detector is wavelength demodulation of Bragg grating fiber optic strain sensors. A strain sensor with resolution of ±6 μϵ was demonstrated using a superluminescent diode and the inline detectors to monitor strain-induced changes in the reflection wavelength of an in-fiber grating     

弯曲长周期光子晶体光纤光栅传感器的研究

为了研究弯曲长周期光子晶体光纤光栅传感器谐振波长漂移量与光栅弯曲形变的关系,采用耦合模理论和计算机模拟方法进行了理论计算和仿真研究,推导出弯曲光子晶体光纤长周期光栅谐振波长表达式,设计了一般弯曲长周期光子晶体光纤光栅传感器系统模型,分析了弯曲长周期光子晶体光纤光栅传感器的基本工作原理,并计算了长周期光子晶体光纤光栅弯曲曲率、光栅有效折射率和谐振波长与弯曲应变的关系。结果表明,随着光栅弯曲形变的增加,光栅的曲率会增加,光栅传感器的谐振波长漂移量会增加,光栅每发生1变化,光栅谐振波长的漂移量变化0.014nm。     

光纤光栅布喇格波长调谐特性的研究

对1550nm光纤光栅在应力作用下布喇格波长的偏萨特性进行了实验研究。当纵向拉伸应力加至367．6克时,得到了5．02nm的调谐范围。这可能是在相同应力作用下,目前所报道的最好结果。