Tunable dispersion compensator based on a fiber Bragg grating written in a tapered fiber

We report a novel dispersion tunable device for first-order dispersion compensation. It is based on a fiber Bragg grating written in a tapered fiber with a specific profile. The taper profile allows tuning the dispersion of the grating by stretching the fiber while the linearity of the group delay is preserved. A device with 0.8 nm of useful bandwidth and dispersion value tunable over more than 400 ps/nm is reported.     

A tunable four-channel fiber Bragg grating dispersion compensator

A tunable four-channel dispersion compensator is achieved using fiber Bragg grating technology and applying a temperature gradient along the grating. Any dispersion from -370 to -1420 ps/nm could be obtained.     

Tunable dispersion equalizer with a divided thin-film heater for40-Gb/s RZ transmissions

We have developed tunable dispersion equalizers with a chirped fiber grating on the divided thin-film heater. The divided thin-film heater took an important role in the control of dispersion and dispersion slope. We successfully demonstrated the dispersion control from -304 to -196 ps/nm, the dispersion slope control from +100 to -300 ps/nm², and good performance in 40-Gb/s return-to-zero transmission by using this tunable dispersion equalizer     

Tunable Dispersion and Dispersion Slope Compensator Using Strain-Chirped Fiber Bragg Grating

We propose a tunable dispersion and dispersion slope compensator based on induced strain-chirp in a uniform fiber Bragg grating. A specially designed mechanical rotator concatenated with a metal beam with linear thickness variation along its height was used to induce a quadratic strain gradient along the grating. We successfully demonstrated the dispersion and dispersion slope change by adjusting the rotation angle and feasibility of dispersion and dispersion slope compensation at 160-Gb/s nonreturn-to-zero transmission by simulation     

可调谐啁啾光栅色散补偿40ps脉冲103km传输实验

本文利用机械调谐的方法对１０ｃｍ均匀光纤光栅进行调谐,实现了光纤光栅的线性啁啾调节,并实现了对２．５Ｇｂ／ｓ１０３Ｋｍ的色散补偿实验,实验结果表明,这种方案不仅对光栅的中心波长可以调节,而且可同时光纤光栅的啁啾系数进行调节。     

一种闭环控制的光纤光栅动态色散补偿仪

利用啁啾光纤光栅的应变调谐特性，将色散补偿的啁啾光纤光栅斜贴于悬臂梁的侧面，通过应力实现啁啾量调整而改变其色散补偿量的大小，同时利用固定在同一悬臂梁的均匀布拉格光栅传感器，实现了闭环自动控制色散补偿量，研制出了一种新型的光纤光栅动态色散补偿仪。该色散补偿仪工作在1550nm波段，典型性能数据为：色散动态补偿范围-1000-1680ps／nm，插入损耗小于1．5dB，动态调谐步进响应时间小于50ms，基本上能满足10Gb／s光纤通信系统中色散动态补偿的要求。     

宽带可调谐光纤光栅色散补偿器系统设计

文章提出一种在光纤光栅自身热膨胀效应产生啁啾的基础上,利用铝片热膨胀系数比较高的特点产生应力来增强光纤光栅啁啾,从而实现了宽带、大范围色散调谐的新型光纤光栅色散补偿器。该色散补偿器能够分别对群速度色散及中心波长独立调谐。实验结果表明,在中心波长为1 551.25nm处,能够实现>1.5nm的色散补偿带宽,-350～-690ps/nm的群时延色散调谐范围;在色散为-660ps/nm情况下,能够实现中心波长1nm的偏移。     

一种新型的光纤光栅可调整偏振模色散补偿器

文章提出一种基于磁场变化对均匀周期光纤光栅(FBG)引入线性啁啾的特性来实现可调整偏振模色散(PMD)补偿的技术。这种全光型PMD补偿技术在实现调整的同时能保持中心波长固定不变，而且能够灵活方便地实现不同的微分群时延量(DGD)。针对10Gbit／s非归fig(NRZ)传输系统，采用这种技术对进行PMD补偿的模拟计算结果表明，接收信号的眼图在补偿后得到了显著改善。     

Tunable dispersion device based on a tapered fiber Bragg grating and nonuniform magnetic fields

We present a new variable dispersion device based on tuning the chirp of a tapered fiber Bragg grating by means of a magnetic transducer. By using a nonuniform magnetic field, we demonstrate a 188-472-ps/nm dispersion tuning range, suitable for tunable radio-frequency filters and dispersion compensation, among others.     

Tunable chirped fibre Bragg grating device controlled by variablemagnetic fields

A novel dynamic chirping fibre Bragg grating device based on a magnetic field applied to a magnetostrictive transducer capable of tuning its dispersion is presented. Chirping ranges up to 300 ps/nm have been demonstrated, which are suitable for several applications such as tunable transversal filtering and dynamic dispersion compensation     

基于非线性啁啾光栅和波长扫描的ROF系统

为了降低光信号在不同传输距离产生的色散对光载射频(ROF)(光载无线电)传输系统的信号质量的影响,提出了一种基于静态非线性啁啾光纤光栅(NLCFBG)和动态波长扫描相结合的可调谐色散补偿ROF传输系统方案。在对所提出系统方案进行理论分析的基础上制作了NLCFBG,并对ROF传输中的可调谐色散效果进行半实物仿真,分析和比较了有无光栅色散补偿时系统的传输性能;验证了此方案对不同传输距离、不同激光频率以及不同射频载波频率的光纤传输系统色散补偿性能。     

Dynamic post dispersion optimization at 40 Gb/s using a tunablefiber Bragg grating

A compact tunable fiber Bragg grating that uses distributed thin-film heaters on the surface of the fiber is used to dynamically optimize the post dispersion compensation of a multi-span 40-Gb/s nonreturn-to-zero (NRZ) transmission system. Dynamic post dispersion compensation with this device enables the system to operate over a much wider range of launch power than is otherwise possible with simple, fixed compensation using dispersion compensating fiber     

Tunable Optical Dispersion Compensator Consisting of Simple Optics With Arrayed Waveguide Grating and Flat Mirror

We propose a tunable optical dispersion compensator (TODC) that uses an arrayed waveguide grating (AWG) and a flat mirror. The TODC employs simple and cost-effective optics, and its chromatic dispersion can be changed simply by translating the AWG. We obtained a 3-dB bandwidth of 39 GHz when the dispersion was tuned within 800 ps/nm, and a maximum dispersion of ${pm}$3000 ps/nm.      

Tunable Optical Dispersion Compensator With Increased Bandwidth via Connection of a Mach–Zehnder Interferometer to an Arrayed-Waveguide Grating

We propose and demonstrate a novel colorless tunable optical dispersion compensator (TODC) consisting of a Mach-Zehnder interferometer (MZI) connected to an ar- rayed-waveguide grating with a thermooptic lens. The MZI approximately doubles the magnitude bandwidth at large dispersion settings. We demonstrate compensation of a 43-Gb/s nonreturn-to-zero signal dispersed over a range of -844 to + 1700 ps/nm. To our knowledge, +1700 ps/nm is the largest demonstrated dispersion compensation amount of a 40-Gb/s signal with a single TODC.     

双束型电子束-CO_2激光器及调谐选支研究

一、引言电子束控制放电的CO_2激光器有高的激光效率和比能输出.然而,由于电子束源本身要损耗电能,使该类器件的效率下降数倍.为了提高这类器件的效率,我们研制成功双束CO_2型电子束激光器(简称DBCO_2L),并进行了调谐选支试验.二、装置DBCO_2L装置示于图1,它是在原8升单束器件的基础上发展起来的,其主要结构参数列于表1.三、调谐实验结果     

Tunable photonic microwave filter with Hi-Bi chirped grating free from chromatic dispersion

A tunable, stable, photonic microwave filter, using a linearly chirped grating in a double-pass configuration, is demonstrated to have a 45 dB notch rejection. This novel configuration overcomes chromatic dispersion and optical coherence interference.     

Two-User 150-km Field Fiber Security Enhanced SPECTS O-CDMA Transmission

We demonstrate two-user error-free performance of security enhanced spectral phase-encoded time-spreading optical code-division multiple-access across a 150-km field fiber link. The testbed incorporates a 64-mode optical frequency comb source, a fully integrated silica arrayed waveguide grating spectral phase encoder/decoder, and a tunable dispersion slope compensator. Physical layer security is enhanced by using a bright code/dark code modulation format     

基于色散光纤环级联结构的可调谐带通微波光子滤波器

提出并验证了一种宽调谐带宽的带通微波光子滤波器设计方案。该滤波器借助可调谐光纤光栅Sagnac环对宽带光源进行均匀切割,产生波长间隔可调的连续光载波作为滤波器的抽头,结合色散光纤环级联结构,实现滤波器的可重构性。研究结果表明,在光电调制器和光电探测器的频率带宽足够大的情况下,当光纤光栅Sagnac环的臂长差在0.50~8.28mm内变化、可调谐光纤延迟线的最小变化步长为0.01mm时,该方案能够实现滤波器中心频率在8.0506~1333.2000GHz内调谐,调谐步长为161.01MHz,边瓣抑制比达到27dB。     

Tunable, picosecond pulse generation using a compressed, modelockedlaser diode source

The generation of pulses shorter than 6 ps, tunable from 1.26 to 1.32 μm, is discussed. The source of these pulses consists of a mode-locked external-cavity 12.3-μm InGaAsP diode laser with grating feedback combined with a compressor which is a grating pair containing an internal telescope. The dispersion in the compressor can be tuned in both magnitude and sign to optimally compensate the chirp in the mode-locked external cavity laser at each wavelength     

Dispersion compensation based on sampled fiber Bragg gratings fabricated with reconstruction equivalent-chirp method

Using uniform phase mask and conventional fabrication technology with submicrometer rather than nanometer precision, a pure third-order dispersion-compensating fiber Bragg grating (DCFBG) and a tunable slope DCFBG are demonstrated with high performance based on the combined reconstruction equivalent-chirp method and an error correction technique. The former DCFBG has a dispersion varying from /spl sim/1000 to /spl sim/-1000 ps/nm in the 100-GHz passband and group delay ripple is less than /spl plusmn/5 ps. The latter has a dispersion slope varying from -150 to 150 ps/nm/sup 2/ within the 3-nm passband, and its group delay ripple is less than /spl plusmn/10 ps.