共查询到17条相似文献,搜索用时 620 毫秒
1.
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
2.
3.
4.
5.
光纤布拉格光栅自致啁啾效应的研究 总被引:3,自引:0,他引:3
根据耦合模理论,采用传输矩阵法分析了相位掩模法制作的光纤布拉格光栅的反射谱特性.设计了一种新的写制光纤光栅的光路,利用高斯激光光束写制出具有短波自致啁啾效应的切趾光栅(栅长0.015 m).对具有短波自致啁啾效应的光纤光栅进行了物理切割(剩余光栅的长度分别取0.007 m和0.0055 m),得到了一种新型的具有长波自致啁啾效应的光纤光栅.原本的自致啁啾光栅反射谱中旁瓣分布在短波长方向,而得到的新型自致啁啾光栅的反射谱中长波长方向的旁瓣更为明显.基于对光纤布拉格光栅自致啁啾效应的分析,提出一种新型类高斯切趾函数,以此函数对自致啁啾效应进行数值模拟,得到了与实验结果相一致的光谱图. 相似文献
6.
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
7.
8.
为了解决传统光纤光栅测温系统中单根光纤上带光纤光栅探头数量少、回波光强弱以及复用能力差的问题,设计研究了基于啁啾光纤光栅的测温系统。通过啁啾调制技术提高了回波光的带宽,从而增强了信号的可处理性并大大提高了带探测点位的数量。推导了啁啾调制的光栅周期表达式,给出了调制方法及波长范围。实验采用LPT-102型宽带光源与F-P光纤解调仪等,调制带宽为1 535.0~1 555.0 nm,并结合WR-201型温度传感器作标定。对20~60 ℃范围内每1 ℃改变进行测试,实验结果显示,传统光纤光栅探头与啁啾光纤光栅探头的测试温度误差相近,都符合设计要求。相比而言,啁啾FBG的测试数据对应的波长偏移具有较为明显的单调线性的特征,即数据稳定性更高,同时,采用啁啾FBG的系统带光纤光栅探头数量明显优于传统光纤光栅测温系统。由此可知,本系统在不增加光纤个数及不降低温度测试精度的基础上,实现了大幅提高带探测点位数量的设计要求。 相似文献
9.
10.
11.
12.
13.
14.
When femtosecond laser pulses interfere with chirped femtosecond laser pulses in As2S3 fiber, a chirped fiber grating is formed. An analytical expression is given to describe the chirped grating, and its Bragg reflectivity is calculated. Because of the high photosensitive effect of As2S3 material, the chirped fiber grating has a wide Bragg reflective spectrum and high reflectivity by choosing proper parameters. This indicates that the chirped fiber grating can be used as a stretcher in the femtosecond chirped pulse amplification (CPA) system. 相似文献
15.
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
16.
17.
High-peak-power laser systems are based on the chirped pulse amplification (CPA) technique. CPA laser system needs a mode-locked laser oscillator for stable ultrashort pulse laser generation. We report a single-mode fiber CPA system which consists of stable mode-locked Yb-doped fiber laser oscillator with a wide tuning range, chirped fiber Bragg grating stretcher, and two Yb-doped fiber amplifiers. The single-mode fibers can generate high-quality and single-mode beams which are stable for long time. 相似文献