全光纤调Q激光器及激光模式的研究

【作者】 魏振兴；

【导师】 袁树忠；

【作者基本信息】 南开大学 ， 光学， 1999， 硕士

【摘要】 近年来,光纤激光器得到了迅猛的发展,特别是短脉冲光纤激光器,由于它在光孤子和光时分复用中的潜在应用,受到越来越多的关注,本文综述了常见的调Q开关和光纤调Q激光器最新发展情况,作者利用光纤M-Z干涉仪作为Q开关,实现了激光器的全光纤化,围绕光纤调Q激光器进行了激光器调谐、自调Q、主动调Q、光纤激光器的模式结构等方面的研究工作。本论文的主要内容有:(1)对光纤光栅激光器的Q开关--光纤M-Z干涉仪的从理论和实验两个方面进行了研究。观测了光纤M-Z干涉仪干涉谱,证明了光纤M-Z干涉仪是一种梳状滤波器。(2)干涉仪在外加信号的驱动下,得到稳定的调Q激光脉冲输出,输出频率在100-999Hz之间连续可调,脉冲占空比为1000:1;峰值功率达1.2W,适当减小干涉仪的自由光谱范围,脉冲宽度进一步被压窄,由原来的4.2μs,压缩到1μs。(3)全光纤调Q激光器,在没有驱动信号的情况下,得到自调Q脉冲,测量了在不同泵浦功率条件下对自调Q现象的影响,并从理论上给予了合理的分析。(4)利用悬臂梁方法调谐光纤光栅实现光纤激光器的波长线性调谐,线性拟合度为0.9997,得到了5.7nm的调谐范围,该激光器的线宽小于0.1nm,输出功率大于1.2mW。(5)利用球面腔扫描干涉仪研究了光纤激光器的模式结构,从理论上对球面腔扫描干涉仪测线宽进行了分析研究,提出了两种窄线宽光纤激光器。更多还原

【Abstract】 Fiber laser, as a new subject, has been developing rapidly in recent years, especially the short pulse fiber laser. Because of its potential application in both optical soliton and optical time division multiplexing communication system in the future, it received more and more attention. In this paper, the author generalizes the latest development of Q-switch laser and introduces the common Q-switch. The author uses fiber M-Z interferometer as Q-switch, realize the fiber laser as all fiber device. We studied the active Q-switching, self-Q-switching, the wavelength tune and the mode structures. The main content is following:(1) In theory and practice, the Q-switch—fiber M-Z interferometer is researched, observed the interferometer spectrum of fiber M-Z interferometer, proving that fiber M-Z interferometer is a kind of comb filter.(2) Fiber M-Z interferometer driven by outside signal, laser put out stable Q-switched laser pulses, the output frequency can be tuned from 100Hz to 999Hz continuously, duty cycle is1:1000, peak power reach 1.2W, if properly decreasing free spectrum range of interferometer, the pulse-width can be further cut down from 4.2μs to 1μs.(3) Without driving signal, all fiber Q-switched lasers can achieve self Q-switched pulse, measuring the effect of different pumped power to self Q-switched and giving reasonable theory analysis.(4) Using Cantilever beam to tune fiber grating to achieve wavelength linear tuning of fiber laser, linear degree is 0.9997, get tuning range of 5.7nm, the width of laser is less than 0.1nm, out-put power is more than 1.2mw.(5) Studying mode structure of fiber laser by spherical surface scanning interferometer, in theory deducing the method of measuring width by spherical surface scanning interferometer, proposing two kind of narrow width fiber lasers.更多还原