掺铥铅硅酸盐玻璃的光谱特性及光子晶体光纤的研究

发布时间：2018-05-05 01:15

本文选题：铥离子 + 铅硅酸盐玻璃　；参考：《华南理工大学》2016年硕士论文

【摘要】：在过去的十年间,连续波和脉冲光纤激光器系统的输出功率得到了前所未有的提高。由于Yb~(3+)的二能级特点,使得高功率光纤激光器的发展主要集中在1.0μm波段。近几年由于在医疗、工业、通讯、国防上的应用要求,2.0μm激光得到了快速发展。目前,在石英和锗酸盐,碲酸盐等多组分玻璃光纤中已实现了2.0μm波段的激光输出,但是由于石英玻璃的稀土离子溶解度较低,锗酸盐拉丝抗析晶性能差以及碲酸盐机械加工性能差的特点,导致2.0μm波段光纤激光器的输出功率难以进一步提高。为实现2.0μm波段高功率激光的输出,解决的途径主要有以下两种:一是增大光纤的有效模场面积,可以有效降低单位面积上功率过高的问题,从而减少光纤非线性效应;二是寻找激光抗损伤阈值、稀土离子的溶解度以及机械加工性能优良的玻璃基质。本文着重从以上两点出发寻求实现2.0μm波段高功率激光输出的有效途径。目前,基于传统光纤在实现单模高功率激光输出困难的问题上,引入了光子晶体光纤。光子晶体光纤比标准传统光纤具有大模场面积,可调的低非线性效应和保持近衍射极限的光束质量优势而受到了广泛关注。本研究瞄准铅硅酸盐玻璃具有低的声子能量、宽的红外透射范围、较高的稀土溶解度、良好的抗析晶性能以及光子晶体光纤的独特优势,开展了对铅硅酸盐光子晶体光纤的研究。以期达到高功率激光输出,成为制备高效率、高功率、2.0μm激光输出的光纤激光器优质增益材料。这在新波段的光通讯、激光等领域具有重要意义。本课题通过调整铅硅酸盐玻璃的组分和改善制备的工艺,优化玻璃的光谱特性和拉丝性能,研究了掺铥铅硅酸盐玻璃光纤制备技术、光纤的性能以及它们间的相互关系。内容包括:(1)研究了铅硅酸盐玻璃组分对Tm~(3+)近2.0μm波段发光性能的影响:在不同浓度Tm2O3掺杂的SiO2-PbO-K2CO3-BaCO3玻璃中,我们发现1 mol%Tm2O3掺杂样品的发光强度最大,并计算了此时Tm~(3+)离子的三个J-O强度参数Ω2、Ω4、Ω6,其值分别为4.81、0.22和0.64,进而计算的1836 nm处的自发辐射寿命为4.89 ms。计算的最大吸收截面σabs为2.8×10-21 cm2,最大发射截面σem为5.67×10-21 cm2,最大增益系数为2.57 cm-1。这些较大的参数值表明此玻璃基质比较适合制备高增益的玻璃光纤。(2)Er~(3+)增强Tm~(3+)近2.0μm波段荧光强度的研究:通过在1 mol%Tm2O3掺杂的SiO2-Pb O-K2CO3-BaCO3-Tm2O3玻璃中引入Er2O3,研究了分别在808和980 nm激光器泵浦下Er~(3+)对Tm~(3+):2.0μm波段的荧光强度的影响,同时,也观察了上转换发光的现象。另外,结合能级图分析了Tm~(3+)/Er~(3+)之间的能量传递机理。通过测试,计算得出在不同泵浦下Er~(3+)→Tm~(3+)之间的能量传递效率分别为67.1%和67.4%。(3)掺铥铅硅酸盐玻璃单模光纤的制备研究:通过对玻璃性能及去除水性能的研究,优选出了适合制备铅硅酸盐玻璃的熔融工艺,并采用管棒法拉制出了数值孔径为0.118,纤芯和包层直径分别为8.4μm和125μm的掺铥铅硅酸盐玻璃光纤。经截断法测试,光纤在1310 nm处的光传输损耗为4.17 dB/m。同时利用1560 nm单模光纤激光器泵浦一段长为3.5 cm的铅硅酸盐玻璃光纤,在1958nm(Tm~(3+):3F4→3H6)波长处观察到了一个半宽高为23 nm的荧光光谱图。(4)掺铥铅硅酸盐玻璃光子晶体光纤的制备研究:基于上章对大块玻璃基质性能的探讨,通过对包层玻璃组分的调整,优选出了适合制备铅硅酸盐光子晶体光纤的玻璃配方并采用打孔法制备了掺铥铅硅酸盐玻璃预制棒及拉制了数值孔径为0.02,纤芯和包层直径分别为30μm和280μm的掺铥铅硅酸盐光子晶体光纤。同时,在显微镜下观察了光子晶体光纤端面。基于理论及软件的模拟,模拟了光子晶体光纤相应的特征参数。经截断法测试,光纤在1310 nm处的传输损耗约为2.91 dB/m。
[Abstract]:In the past ten years, the output power of CW and pulse fiber laser systems has been improved unprecedentedly. Due to the two level characteristics of Yb~ (3+), the development of high power fiber laser is mainly concentrated in the 1 U M band. In recent years, the 2 u m laser has been fast due to the requirements of medical, industry, communication, and national defense. At present, the 2 M band laser output has been realized in the multi component glass fiber of quartz and germanate, tellurite and so on. But because of the low solubility of the rare earth ion in the quartz glass, the poor anti crystallization performance of the germanate salt drawing and the poor processing performance of the tellurite, the output power of the 2 M band fiber laser is difficult. In order to further improve the output of high power laser in 2 M band, there are two main ways to solve the problem: one is to increase the effective mode field area of the optical fiber, reduce the problem of high power in the unit area, and reduce the nonlinear effect of the fiber. Two is to find the laser damage threshold, the solubility of the rare earth ions and the machine. This paper focuses on the effective way to realize high power laser output in 2 M band from the above two points. At present, photonic crystal fiber is introduced on the basis of traditional optical fiber to realize the difficulty of single mode high power laser output. In this study, lead silicate glasses have low phonon energy, wide infrared transmittance, high rare-earth solubility, good anti crystallization properties and unique advantages of photonic crystal fiber, and lead silicate light is carried out. The study of the crystal fiber, in order to achieve high power laser output, becomes a high quality gain material for producing high efficiency, high power, 2 u m laser output fiber laser. This is of great significance in the field of optical communication, laser and other fields in the new band. This topic is to optimize the composition of the lead silicate glass and improve the preparation process to optimize the glass light. The preparation technology of thulium doped lead silicate glass fiber, the properties of fiber and their relationship are studied. The contents include: (1) the effects of the lead silicate glass components on the luminescence properties of Tm~ (3+) in the near 2 U M band are studied. We found 1 mol%Tm2 in the SiO2-PbO-K2CO3-BaCO3 glass doped with different concentrations of Tm2O3. The luminescence intensity of the O3 doped sample is the largest, and the three J-O intensity parameters Omega 2, Omega 4, Omega 6 of the Tm~ (3+) ion are calculated at 4.81,0.22 and 0.64 respectively. The maximum absorption section of the 1836 nm at 4.89 Ms. is calculated and the maximum absorption cross section is 2.8 * 10-21 cm2, and the maximum emission section is 5.67 * 10-21 cm2, the maximum gain system The larger parameter values of 2.57 cm-1. indicate that the glass matrix is more suitable for the preparation of high gain glass fibers. (2) a study on the fluorescence intensity of the near 2 U M band of Er~ (3+) enhanced Tm~ (3+): Er2O3 was introduced in the SiO2-Pb O-K2CO3-BaCO3-Tm2O3 glass doped with 1 mol%Tm2O3, and the pair was studied under the 808 and 980 nm lasers, respectively. Tm~ (3+): the effect of fluorescence intensity on 2 mu m band, and the phenomenon of upconversion luminescence is also observed. In addition, energy transfer mechanism between Tm~ (3+) /Er~ (3+) is analyzed with energy level diagram. The energy transfer efficiency of Er~ (3+) to Tm~ (3+) between Er~ (3+) and Tm~ (3+) under different pumps is calculated, and 67.1% and 3 thulium doped lead silicate, respectively, are calculated. Study on the preparation of glass single mode fiber: through the study of the performance of glass and the performance of water removal, the melting process suitable for the preparation of lead silicate glass was optimized. The thulium doped lead silicate glass fiber with the numerical aperture of 0.118, the core and the cladding diameter of 8.4 m and 125 um m were produced by the tube bar. The fiber was tested by truncation, 131 The optical transmission loss at 0 nm is 4.17 dB/m. and a 1560 nm single mode fiber laser is used to pump a lead silicate glass fiber with a length of 3.5 cm. The fluorescence spectra of 1.5 wide and 23 nm are observed at the wavelength of 1958nm (Tm~ (3+): 3F4 / 3H6). (4) the preparation of thulium doped lead silicate glass photonic crystal fiber: Based on the upper chapter The properties of large glass matrix are discussed. By adjusting the components of the cladding glass, the glass formula suitable for the preparation of lead silicate photonic crystal fiber is optimized and the thulium doped lead silicate glass preform has been prepared by punching method and the thulium doped lead silicate with the numerical aperture of 0.02, the core and the cladding diameter of 30 m and 280 m respectively is made. At the same time, the end surface of the photonic crystal fiber is observed under a microscope. Based on the simulation of theory and software, the corresponding characteristic parameters of the photonic crystal fiber are simulated. The transmission loss of the optical fiber at 1310 nm is about 2.91 dB/m. by truncation.

【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TQ171.1

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