【作者】 王静；

【导师】 简水生；

【作者基本信息】 北京交通大学 ， 光通信与移动通信， 2012， 博士

【摘要】 光纤中前向Brillouin散射的色散曲线在零波矢处近似平坦,能用于产生梳状频率、光衰减器、锁模光纤激光器和光存储等领域。本文从理论和实验详细分析了125μm标准光纤中的横向声学模和前向Brillouin散射,首次在实验中观察到2km高非线性光纤(HNLF)中前向自发Brillouin散射(GAWBS)和高增益的前向受激Brillouin散射(FSBS)现象；结合新型稀土掺杂光纤的研制,提出了一种多偏振控制全光纤Sagnac环滤波器件。主要取得的成果如下：1.建立了横向声学振动模、极化GAWBS和去极化GAWBS散射的散射效率分析模型,首次在2km HNLF中分别观察到散射很大的极化GAWBS和去极化GAWBS光谱,散射效率和散射频率与理论计算完全一致。2.建立了标准光纤中前向受激类拉曼Brillouin散射(SRLS)和前向受激去极化Brillouin散射(SIPS)的增益和振幅分析模型。模型考虑了所有声学振动模式的存在,揭示了Kerr非线性效应对SRLS增益的大小和线型影响,由于Kerr非线性效应的存在,斯托克斯光和反斯托克斯光的增益变大、线宽变宽；增益谱失去了洛仑兹线型；增益的峰值频率偏离中心频率,向低频处移动。3.首次观察到2km标准HNLF中,频率范围从425MHz到1.1GHz的SRLS增益谱,当输入泵浦光8mW时增益峰值出现在振动频率933.8MHz处,增益因子34.7W-1,比Kang等人在Nature Physics上报道的实验值高三倍。揭示了振动模线宽的产生机制,以及注入泵浦光、斯托克斯光和反斯托克斯光的初始相位对SRLS增益的影响。4.提出一种包含多偏振控制的Sagnac环滤波器件,建立多级Jones矩阵分析法对透射输出特性进行分析。多偏振控制Sagnac具有波长间隔可调和边频抑制等优点；透射谱的偏振可调性随偏振控制级数的增加而增强,实验结果与理论研究一致。5.研制了一种新型的高性能稀土掺杂光纤,并实现了单偏振控制Sagnac环和双偏振控制Sagnac环选频调谐的环形腔掺铒光纤激光器。实验中调节PC分别得到了单波长、双波长和多波长激光输出。单偏振控制下得到了输出斜率效率为20%,3dB线宽0.016nm,30dB线宽0.097nm,边模抑制比(SMSR)40dB左右的稳定激光输出。双偏振控制下的3dB和30dB线宽小于0.03nm和0.06nm,室温下30分钟内峰值波长和功率波动小于0.05nm和0.1dB,激光输出的边模抑制比单偏振控制的情况提高了近5dB。更多还原

【Abstract】 The acoustic waves form optical-phonon-like modes of forward Brillouin scattering has a flat dispersion curve; so it is suggested that the process may be used in a wide variety of photonic applications, such as frequency comb generation, active phase modulation, optical frequency conversion, and high-frequency mode locking of fiber lasers. In this paper, the transverse acoustic mode and forward Brillouin scattering are theoritecal and experimentally studied in standard fibers of125μm. The filter chacteristics of Sagnac loops are studied with the fabrication of rare-earth doped fibers. And the main achievements of this thesis are listed as follows:1. An analytical model of transverse acoustic mode, polarized GAWBS and depolarized GAWBS is established. The polarized and the depolarized GAWBS are observed in a2-km-long highly nonlinear fiber (HNLF) respectively. And the scattering efficiency and the frequency agree with the calculation.2. An analytical model of forward stimulated Raman-like Brillouin scattering (SRLS) and forward stimulated inter-polarization scattering (SIPS) is established, considering all the acoustic modes. It is revealed that the influency of Kerr nonlinearity on the gain and lineshape of SRLS. The gain of (anti-) Stokes beam increases; the linewidth of (anti-) Stokes beam broadens and the profile on the anti-Stokes side of the pump beam have lineshapes that are asymmetric; peak of gain deviating from centual frequency shifts to lower frequency.3. A SRLS gain specture is observed first time. When a pump of8mW is launched into HNLF, the tight confinement of the light and acoustic field enhances the interaction and results in a large gain coefficient of34.7W’1at a frequency of933.8MHz; which is three times of Kang’s report in Nature Physics. It is releaved that the generation machine of lineshape and the influence of initial phase of input signals on the gain.4. A multi-polarization controlled Sagnac loop is proposed; and an analytical method of multi-order Jones matrix is established. And the results show that the more polarization controls the more flexible the transmission spectrum is; the interval tunability and the side-frequency restriction are shown. The experimental results are in great agreement with theory. 5. A kind of new type high features single cladding highly rare-earth doped silica optical fiber was fabricated by a new furnace round heating MCVD process.; and the erbium-doped ring fiber lasers based on a single polarization controlled Sagnac loop filter and a double polarization controlled Sagnac filter are proposed. In experiment Stable single-, double-and triple-wavelength are achieved respectively. The stable laser with20%slope efficiency,0.016nm3dB line-width,0.097nm30dB line-width and40dB SMSR is obtained by using a single polarization controlled Sagnac. By using double polarization controlled Sagnac, the3dB line-width is less than0.03nm, and the fluctuation of wavelength and peak power is less than0.05nm and0.1dB in30minutes. The side-frequency restrain characteristic is shown in a ring fiber laser for its application in our paper; and the SMSR enhances5dB.更多还原