DWDM系统中的光滤波技术

全面介绍了目前密集波分复用系统中的主流光滤波技术，包括介质薄膜滤波器、阵列波导光栅、光纤光栅、熔锥器件、奇偶交错滤波器和声光可调谐滤波器，从系统应用的角度分析了光滤波技术的发展趋势。     

一种基于光纤光栅传输色散特性的可调谐色散补偿方案

分析了光纤光栅在禁带附近的光特性,提出了一种基于光纤光栅传输色散特性和应用变特性的新的色散补偿方案－级联光纤光栅可调谐色散补偿;从理论和实验两方面分析了它的色散补偿的可调谐性,并进行了数值模拟;讨论了这种方案在光纤通信方面特别在密集波分复用系统中的应用前景。     

基于可调谐激光器的复用传感系统的研究

为了克服复用传感系统中光源带宽及功率的制约,有效地扩大多点检测的范围,采用波分和时分复用传感技术,设计了可调谐光纤激光器作为传感系统的光源.基于耦合模方程的理论,对匹配光栅调谐光纤激光器波长扫描寻址解调方法进行了理论分析和实验研究.实验中采用可调谐光纤激光器对由4个光栅组成的两个光栅串成功地进行了波分和时分复用传感,实验获得的应变分辨率为2.9με/step.该传感系统具有经济实用性、信噪比高、可复用数目大等特点,对于多点检测的传感网络具有较大的实用价值.     

一种新颖的宽带可调光纤光栅滤波器

分析了光纤光栅（FBG）调谐的基本原理,进而采用新颖的调谐结构,设计并实现了一种宽带可调谐的FBG滤波器。该滤波器仅用1支FBG制做而成,其波长调谐范围最高可达40nm。实验结果表明,该FBG滤波器的调谐波长与调谐步进位移量之间具有良好的二次曲线关系。     

可调谐光滤波器的研究

可调谐滤波器在光纤通信和光纤光栅传感中发挥了重要的作用.分别介绍了几种常用的可调谐光滤波的原理、结构和性能,分析了其发展趋势.     

LiNbO3声光可调谐滤波器(AOTF)在OADM中的应用

基于LiNbO3晶体的声光可调谐滤波器（AOTF）是利用TE／TM模式转换的原理实现了多波长选择特性和宽调谐范围，这使它在波分复用（WDM）中的光分插复用（OADM）系统中有广泛用途，文章介绍了AOTF的基本原理，以及用它的构成的OADM系统。     

集成LiNbO3声光可调谐滤波器及其在WDM光网络中的应用

针对基于LiNbO3的集成声光可调谐滤波器(IAOTF)具有调谐范围宽、滤波带宽窄、调谐速度快、驱动功率低以及同时可实现多波长选择等优点,它在波分复用(WDM)光网络光插分复用(OADM)系统中具有广泛的应用前景.介绍了IAOTF的基本原理及特性,国内外发展状况和研究重点以及它在WDM光网络中OADM应用.     

基于可调谐FP滤波器的光纤光栅解调系统

为了进一步提高光纤光栅解调系统的性能,提出和研究了一种新颖的基于可调谐F-P(Fabry-Perot)滤波器的光纤光栅解调技术,并以此为基础构建了探测系统。系统使用一个固定波长的参考光纤光栅作为波长参考元件,通过对传感光纤光栅与参考光纤光栅的波长测量与差值运算,消除了可调谐FP滤波器腔长漂移对测量精度的影响。给出压电陶瓷电压对应的伸长量,有效地减小了压电陶瓷非线性对测量的影响,提高了光纤光栅波长的测量精度。在测量范围内,最大非线性偏差为0.5%。     

重叠写入啁啾光纤光栅型滤波器的研究进展

高性能的波分复用器是密集波分复用系统的核心器件之一,重叠写入啁啾光纤光栅型带通滤波器充分发挥了光纤光栅优良的波长选择特点,是一种低成本的新型全光纤波分复用器件.综合评述了各种不同结构的重叠写入啁啾光纤光栅型滤波器的工作原理、基本特点及其应用.     

LiNbO3声光可调谐滤波器(AOTF)在OADM中的应用

基于LiNbO3晶体的声光可调谐滤波器(AOTF)是利用TE/TM模式转换的原理实现了多波长选择特性和宽调谐范围,这使它在波分复用(WDM)中的光分插复用(OADM)系统中有广泛用途.文章介绍了AOTF的基本原理,以及用它构成的OADM系统.     

基于应变的多模光纤可调谐光纤滤波器设计

可调谐光纤滤波器技术是波分复用系统的关键技术之一,对于发展全光通信网络和光纤传感具有极其重要的意义。提出了一种基于大芯径的多模光纤可调谐带阻滤波器,其制作方法是将包层/纤芯直径为125/105μm的特种多模光纤通过单模光纤接入光纤系统,实现单模-多模-单模(SMS)光纤结构,并使一端单模光纤与多模光纤熔接,另一端只是共轴对接而不焊接。在多模干涉原理的基础上,利用该结构对应变的敏感性实现可调谐光滤波。该可调谐滤波器的调制和解调借助于放大自发辐射(ASE)宽谱光源和光谱分析仪(OSA)实现。详细给出了该滤波器的理论仿真分析,并实验证实了该方案的有效性。     

Digitally tunable wavelength filter and laser

A novel nonmechanical, digitally tunable, polarization insensitive and optically transparent wavelength filter using holograms electro-optically written on a ferroelectric liquid crystal (FLC) spatial light modulator (SLM) has been constructed and operated to tune to discrete wavelengths spaced by 1.3 nm. The filter has been incorporated in a ring laser which is tunable over a range of 38.5 nm across the erbium window, giving output powers of 10 mW. Both wavelength filter and tunable laser are suitable for wavelength division multiplexing (WDM) applications.     

用可调谐F-P干涉滤波器

简述了采用可调谐F－P干涉滤波器对DWDM合路光信号性能指标进行在线监测的特点,分析了F－P干涉滤波器的频谱特性,结合EDM信号的特点与测试技术要求,提出了一种利用数字图像处理技术进行数据复原与变换的处理方法。     

An adaptive wavelength tunable optical filter employing anangle-tuned interference filter and an intelligent digital controller

This paper describes an adaptive wavelength tunable optical filter, which is composed of an angle-tuned interference optical filter and an intelligent digital controller. The new angle-tuned interference filter consists of a dielectric interference optical filter and a piezoelectric angle-tuning mechanism. It achieves quick wavelength switching within 2.5 ms in a 30 nm tuning range and a sufficiently low crosstalk less than -30 dB. The intelligent digital controller has two functions: wavelength tracking and wavelength channel selection. Combining these technologies, we have developed a practical low-cost tunable filter suitable for a post-optical-amplifier filter in a high-sensitivity detection system and a channel selector in a WDM system that requires 10-100 ms channel selection time. With a wavelength tracking operation, we have confirmed -35 dBm high-sensitivity detection in 20 nm wavelength range in a 10 Gb/s system. We have also confirmed a wavelength channel selection operation within 18 ms in a three-channel wavelength division multiplexed (WDM) system whose channel spacing is 4.4 nm     

Wide tuning range and low operating power AWG-based thermo-opticwavelength tunable filter using polymer waveguides

Two types of polymer thermo-optic wavelength tunable filter (TOWTF) have been developed, each with a pair of triangular phase shifters. One filter is designed for a large-scale WDM system (32 channels, 0.8 nm spacing), the other for a small-scale WDM system (10 channels, 0.8 nm spacing). The arrayed waveguide number is optimised thus reducing the operating power required by the filters. Moreover, both filters operated with a low crosstalk of <-25 dB     

Wavelength-tunable add/drop optical filter

A new type of add/drop optical filter discretely tunable along equally spaced channels is presented. This device may have very useful applications in WDM optical networks.     

Tunable optical filters for dense WDM networks

WDM is currently taking over as the leading technology in point-to-point transmission links. For optical implementation of WDM networks, logical functionalities such as wavelength (channel) selection should be carried out in the wavelength domain; thus, the development of dynamic optical devices is required. One key device is a tunable optical filter. Important features of such a filter include low insertion loss, narrow bandwidth, high sidelobe suppression, large dynamic range, fast tuning speed, a simple control mechanism, small size, and cost effectiveness. Here, an extensive overview of the different technologies used to produce tunable optical filters is presented. Among them, fiber filters such as fiber Bragg gratings and fiber Fabry Perot are the most commercialized, yet inherently limited in their dynamic speeds. For high demanding dynamics, micro-machined and acousto-optic filters can offer a good solution for microsecond tuning speeds. Faster tunable devices, in nanosecond tuning speeds, might emerge out of microresonators, electrooptic filters, and active DBR filters     

Widely tunable chaotic fiber laser for WDM-PON detection

A widely tunable high precision chaotic fiber laser is proposed and experimentally demonstrated. A tunable fiber Bragg grating （TFBG） filter is used as a tuning element to determine the turning range from 1533 nm to 1558 nm with a linewidth of 0.5 nm at any wavelength. The wide tuning range is capable of supporting 32 wavelength-division mul- tiplexing （WDM） channels with 100 GHz channel spacing. All single wavelengths are found to be chaotic with 10 GHz bandwidth. The full width at half maximum （FWHM） of the chaotic correlation curve of the different wave- lengths is on a picosecond time scale, thereby offering millimeter spatial resolution in WDM detection.     

1*2 polarisation-independent acousto-optic filter tunable over 1.30-1.56 mu m

A polarisation-independent, electronically tunable, acousto-optic filter made with commercially available components is demonstrated. It has a bandwidth (FWHM) of 4 nm, two complementary outputs, a fibre-to-fibre insertion loss of 6-8 dB, and is continuously tunable over 1.30-1.56 mu m. It is suitable for use in multiaccess WDM networks requiring approximately=microsecond-tuning time.<>     

Polarization independent, linear-tuned interference filter with constant transmission characteristics over 1530-1570-nm tuning range

We present a polarization independent optical tunable filter (OTF) with nearly constant transmission characteristics over 1530-1570 nm. The tuning is achieved by horizontally sliding an interference filter, resulting in a very low polarization dependent loss (PDL)<0.1 dB and nearly constant characteristics over the tuning range. By cascading interference filters in double or triple stage, narrower bandwidth characteristics are obtained allowing for smaller channel spacing in wavelength division multiplexing (WDM) systems. Experimental results for PDL, loss, and bandwidth are presented and compared to those of angle-tuned filter. The proposed OTF has shown superior performance promising a practical solution for dense WDM applications.