共查询到19条相似文献,搜索用时 140 毫秒
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针对啁啾光纤光栅的带通滤波特性,设计了纤芯/包层复合结构的啁啾光纤光栅滤波器。基于光纤耦合模和传输矩阵理论及坐标变换方法,对其光谱特性进行仿真分析,验证了该光栅的双带通滤波特性;对周期为536、537、538nm,长度为8、10、12mm,折射率调试深度为0.0002、0.0003、0.0004,啁啾系数为0.05、0.10、0.15nm/cm的该结构光栅进行光谱模拟,证明中心波长随周期增大而增大;半峰宽度随长度、调制深度、啁啾系数增大而变宽;反射率峰值随啁啾系数增大而降低,随调制深度增大而升高。上述研究证明了该结构光栅具有双带通滤波特性,且幅值带宽可调。 相似文献
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利用有机玻璃块和螺旋测微器组成的简支梁系统调谐线性啁啾光纤光栅,将中心波长为1548.6nm、3dB带宽为0.43nm、长为25mm的均匀Bragg光纤光栅按一定角度牢牢的固定在一块长为90mm,宽为10mm,高为5.2mm的有机玻璃块中,再用螺旋测微仪在有机玻璃的中心位置向下施加压力,使简支梁及其中的光纤光栅变形,成为可调谐的啁啾光纤光栅。实验结果表明啁啾光纤光栅反射谱宽与简支梁弯曲量成线性关系,当简支梁最大弯曲量为1.2mm时光纤光栅反射谱展宽了4.02nm,而反射中心波长基本不变,该实验装置可以用于光控相控阵雷达天线的实时延迟线和光纤色散补偿。 相似文献
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用布拦格光纤光栅制作啁啾光纤光栅 总被引:1,自引:1,他引:0
介绍了一种用布拉格光纤光栅制作啁啾光纤光栅的方法。采用氢酸腐蚀布拉格光纤光栅,使光栅的横截面沿光栅轴向逐渐变小,然后对光栅施加1.50N的拉力,在光栅轴向建立应变梯度,制作出长15mm、峰值反射率达92%、反射半高宽为5nm的啁啾光纤光栅。 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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利用均匀相位掩模板制作线性啁啾光纤光栅 总被引:3,自引:1,他引:2
理论上分析并从实验上验证了一种利用均匀相位掩模板写入啁啾光纤光栅的方法:将光纤弯曲,由于光纤离掩模板的距离不同从而使光纤光栅的周期轴向渐变,由此产生啁啾。分析了这种啁啾光纤光栅的谱特性和时延特性,同时也分析了由于光纤离掩模板的距离不同而引起的折射率调制变化给光纤光栅特性带来的影响。设计了一种石英曲面,利用其使光纤按照弯曲函数进行弯曲,然后进行紫外曝光制成了线性的啁啾光纤光栅。实验中制作的啁啾光纤光栅色散值为-1102 ps/nm,纹波为17ps。通过改变弯曲函数就可以实现利用一块均匀相位掩模板制作不同啁啾量的啁啾光纤光栅的目的,降低了啁啾光纤光栅的制作成本。 相似文献
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By introducing a convergent lens in the phase mask setup and by tilting appropriately the fiber from the phase mask, a linearly chirped fiber grating with an appropriate chirp can be obtained conveniently. Using this method, two groups of fiber gratings, each of them is composed of 8 overlaped linearly chirped fiber gratings but with different center reflection wavelength separations (~0.8 nm and ~1.6 nm, respectively) are fabricated. Experimental results show that, the compensators based on the two groups of fiber gratings can be used to compensate for the dispersion of 8×2.5 Gb/s transmission over 100 km of standard single-mode fiber for multiple channels in optical time-division multiplexing (OTDM) and densed wavelength division multiplexing (DWDM). 相似文献
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Dispersion Compensators Based on Overlaped Linearly Chirped Fiber Gratings for DWDM Systems 总被引:1,自引:0,他引:1
1 Introduction ThereisagreatdealofinterestinfiberBragggratingsduetotheirmanyimportantapplicationsinthefieldoftelecommunicationsandfibersensors .BecausefiberBragggratingsexhibitdispersionbothinreflection ,especiallywhenthe gratingischirped[1] ,andintransm… 相似文献
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双波长啁啾相移光纤光栅 总被引:2,自引:2,他引:0
理论研究并实验验证了一种含有两段π相移的啁啾相移光纤光栅.采用F矩阵对啁啾相移光纤光栅进行计算并分析了该光栅的谱特性.含有两段π相移的啁啾相移光纤光栅可以在普通啁啾光栅透射谱阻带中产生双波长透射峰,透射峰位置直接取决于光栅中π相移的位置,透射峰的线宽和透射峰的波长间隔没有关系,仅随着啁啾率的增大而增大.采用带相位掩模的逐点扫描法对含有两段π相移的双波长啁啾相移光栅进行了制作,获得波长间隔为8 nm的双波长透射谱的光栅器件.该光栅的消光比和3 dB谱线宽分别为20 dB和0.08 nm,实验结果和理论设计一致. 相似文献
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Jianliang Yang Yunqi Liu Sweechuan Tjin Jianping Yao 《International Journal of Infrared and Millimeter Waves》2002,23(8):1241-1250
A photonics true-time-delay system for phased array antenna beam steering employing a novel tunable chirped fiber grating delay line and a multi-wavelength erbium-doped fiber ring laser source based on a sampled grating filter is proposed. The tunable chirped fiber grating, which act as a continuous time-delay element, is achieved by bending a uniform fiber Bragg grating bonded at a slant onto the lateral surface of a simply supported beam. This technique allows the dynamic control of the chirp rate and spectral width of the grating without center wavelength shift. By adjusting the chirp rate of the fiber grating via bend strain, this kind of tunable chirped fiber grating could achieve very low and adjustable delay times, therefore provides higher angle resolution for scanning microwave beam, even the wavelengths of laser source are fixed and un-tunable. The true-time-delay system using proposed tunable chirped fiber grating delay element and sampled grating based laser source is constructed and demonstrated experimentally. 相似文献
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A CO2 laser and point-by-point method are used for fabricating step-changed period chirped long-period fiber gratings (LPFG). Several types of period chirped LPFGs have been demonstrated, such as, linearly chirp, peak-shape chirp, and cascaded linearly chirp. Unlike uniform LPFGs, the spectrum change such as multiple attenuation peaks, broader spectrum can be seen in these chirp gratings, and the spectral shape can be controlled by the grating period. Especially, the cascaded linearly chirped LPFGs performs a multi-peak as interference between the core mode and cladding mode, which can be used as multi-wavelength filters in fiber optic communication and fiber optic sensors. Also, a linear tuning range of 1.6 nm with -0.559 pm/με tuning rate is achieved in these types of devices by applying an axial strain. 相似文献
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Jianliang Yang 《Fiber and Integrated Optics》2003,22(4):239-247
A novel multiwavelength linear-cavity fiber laser source using a strain-induced chirped fiber Bragg grating, a Sagnac interferemetric filter, and Erbium-Ytterbium codoped fibers is proposed and demonstrated for the first time. The Sagnac interferemetric filter, which acts as a full-reflecting mirror, consists of a polarization-maintaining directional coupler and two pieces of polarization-maintaining fibers. The strain-induced chirped FBG, which acts as a partial-reflecting mirror, is achieved by bending a uniform FBG bonded at a slant onto the lateral surface of a simply supported beam. By tuning the strain-induced chirped FBG, desirable lasing wavelength and number can be easily achieved. 相似文献