【作者】 张料林；

【导师】 邱建荣；

【作者基本信息】 华南理工大学 ， 材料学， 2014， 博士

【摘要】 激光技术是二十世纪最伟大的发明，深刻影响了当代科学技术和社会经济的发展。激光玻璃作为激光的最重要工作物质，由于其自身一系列的优势，使得它在激光技术中的应用越来越广泛。随着激光技术的发展，对增益介质的要求越来越高、越来越多样化，以实现不同性质的激光输出。本论文就应用于可见和近红外激光玻璃的基础及应用展开了系统的研究。全文共分成六章，包括绪论、实验及基础理论、可见波段激光玻璃基础研究、铋掺杂玻璃发光特性研究、掺杂磷酸盐玻璃光纤研制、飞秒激光诱导掺杂磷酸盐玻璃及光纤折射率的基础研究，飞秒激光在掺杂磷酸盐玻璃中直写光波导的基础研究、以及结论等部分。第一章首先介绍了激光玻璃的发展历史、可见光光纤激光器的研究进展和铋掺杂光纤激光器研究进展以及铋掺杂玻璃发光机理的研究历史。由于目前应用于可见波段光纤激光器的增益介质主要为以掺杂氟化物光纤，这种以氟化物作为光纤基质的材料化学稳定性及抗热冲击性能比较差，很难以满足高功率可见光激光器对工作物质的要求。如果利用化学稳定性和机械性能较优氧化物玻璃来替代氟化物玻璃，将可以大幅度的提高光纤激光器性能。第二章主要介绍了实验及测试方法，广泛应用于激光玻璃性能参数计算的J-O理论和McCumber理论，以及与本论文相关的稀土离子无辐射跃迁理论。第三章我们从玻璃组成出发，选择四种典型的氧化物玻璃，系统研究了Sm3+、Pr3+、Tb3+掺杂四种氧化物玻璃的光谱特性。详细解释了基质对Pr3+发光性能的影响。提出对于Pr3+掺杂激光玻璃的设计所需考虑的因素。低声子能量的玻璃基质适合于作为Pr3+来自于3P0能级的发光。通过计算Sm3+掺杂四种氧化物玻璃的激光参数，得出磷酸盐玻璃基质的吸收和受激发射截面都大于锗酸盐、硅酸盐和碲酸盐玻璃，且与Sm3+掺杂的石英玻璃大一个数量级，更适合于作为光纤激光器的增益介质材料。在Tb3+掺杂磷酸盐玻璃浓度达到15mol%而没有出现浓度淬灭现象，而在硅酸盐、锗酸盐玻璃中掺杂浓度达到3mol%即出现浓度淬灭现象，10mol%Tb3+掺杂磷酸盐玻璃的实际测量量子效率高达78%。第四章我们系统的研究了铋掺杂石英玻璃随激发波长的改变发射波长无规律性变化的现象，通过总结已有的现象及结合实验结果，提出铋掺杂石英玻璃中存在两个发光中心，为Bi+和Bi0，分别对应于铋掺杂石英玻璃中的短波长和长波长发光。根据Moore能级图构建Bi+和Bi0的能级模型，利用构建的模型很好的解释了铋掺杂石英玻璃中发射波长随着激发光波长的改变及玻璃预制棒和光纤发光相异的现象。且利用该模型很好的解释了铋掺杂石英玻璃光纤预制棒的在拉制成光纤之后产生变化的原因。第五章就光纤的研制展开了研究。首先利用管棒法制备了Tb3+掺杂磷酸盐玻璃光纤，制备出来的光纤在1310nm的传输损耗为3.18dB/m。与目前应用于超窄线宽光纤激光器用的掺杂磷酸盐玻璃光纤损耗相当。采用堆积法制备出Tb3+、Nd3+掺杂的磷酸盐玻璃光纤，采用截断法测试光纤的损耗分别为10.6dB/m和6.453dB/m。堆积法制备光纤相比于管棒法制备掺杂光纤，从原理上来讲，由于其去除了玻璃打孔及孔抛光的过程，光纤的纤芯和包层的界面是通过热处理的过程接触在一起，理应损耗要更低，但是由于光纤组分的设计及拉丝温度的不适当造成组成包层的细棒没有完全融合成一体，且由于表面张力的作用，纤芯在软化之后被吸入到包层细棒的间隙中间，纤芯的形状变为正六边形，导致光纤损耗剧增。在前面激光玻璃及光纤研制的基础上，我们采用飞秒激光在制备的掺杂磷酸盐激光玻璃中刻写光波导，通过改进参数制备出双线波导。利用632nm的He-Ne激光器进行光波导传输实验，发现制备出来的光波导可以很好的传输单模激光，经过光波导后传输光的模式仍为高斯分布的基模模式。利用飞秒激光在拉制出来的Yb3+掺杂磷酸盐玻璃光纤中进行折射率的调制，通过调节加工参数，得到规整的周期性折射率调制，为下一步的光纤光栅的刻写提供了重要的工艺参数。更多还原

【Abstract】 Laser technology is the greatest invention of the twentieth century, has taken a profoundimpact on the development of modern science, technology and social economy. Due to itsown set of advantages, laser glasses have been widely used in the laser technology. However,with developing of laser technology, more diverse and higher quality laser glasses should tobe developed to achieve high power, new wavelength laser output.This dissertation is focused on the basic study of laser glasses. The dissertation iscomposed of introduction, measurement methods and relative theory, visible fiber laserglasses, bismuth doped glass, rare-earth doped phosphate glass fiber, femtosecond directwriting waveguide and fiber gratings in rare-earth doped phosphate glass and fiber.Chapter1introduces the definition of laser glass and research progress of visible fiberlaser, bismuth doped material and bismuth doped fiber laser.Chapter2introduces the sample preparation and experiment measure methods, J-O andMcCumber theorys, non-radiative mechanisms of non-raditive transitions of rare earth ions.In chapter3, we systematically study the spectroscopic properties of Sm3+, Pr3+andTb3+-doepd oxide glasses. We comparatively study the spectroscopic properties of Pr3+-dopedphosphate, silicate and tellurite glasses. The emissions from Pr3+-doped boro-phosphate,boro-germo-silicate and tellurite glasses show different decay behaviors and can be wellexplained by multiphonon relaxation theory. We demonstrated that Sm3+-doped phosphateglass is more suitable as gain medium for visible fiber laser, since its absorption andstimulated emission cross sections lager than Sm3+-doped other three oxide glsses, and alarger magnitude than Sm3+-doped silica glass fiber. For green fiber laser, Tb3+-dopedphosphate is the most suitable gain medium, since no concentration quenching were observedin Tb3+-doped phosphate glass when Tb3+concentration is up to15mol%. And thefluorescence quantum efficiency of10mol%Tb3+-doped glass is up to78%.In chapter4, we study the dependence of NIR luminescence of a Bi-doped silica glasson the excitation wavelengths in the range of280-980nm. The emission peak of the Bi-dopedsilica glass shows a complex change between1120nm and1270nm when the excitationwavelength change from280nm to980nm. We assign NIR emissions at1120nm and1270 nm to3P1→3P0transition of Bi+and2D3/2→4S3/2transition of Bi0, respectively. Tentativeenergy level diagrams for Bi+and Bi0are proposed according to the absorption spectra andexcitation spectra of the glass sample. The proposed model can well explain the observedluminescent phenomena.Chapter5describes designing and fabrication methods of rare earth dopedmulti-component glass fibers. We fabricated Tb3+-doped phosphate glass fiber by usingrod-in-tube method. The optical loss at1310nm of obtained fiber is measured to be3.18dB/m. And we also designed and fabricated Tb3+, Nd3+-doped phosphate glass fibers by usingstack-and-draw method. The optical losses at1310nm are10.6dB/m and6.453dB/m,respectively. We fabricated fiber grating structures in rare earth doped phosphate glass fiberby femtosecond direct writing method. We also fabricated waveguide in rare earth dopedphosphate laser glass, and we successfully couple the single and multi mode laser into thewaveguide.更多还原