结构调控研制新蓝绿光激光自倍频晶体

All solid state laser devices are compact, stable, high efficiency and with small volume, and they have large applications in many fields. Using the technique of self-frequency-doubling to obtain green and blue laser light has special advantage, in which the core is self-frequency-doubling (SFD) crystal. But, so far, there is no such mature product. Using the structure-controlled method, adding Nb ions into Nd:YCa9(VO4)7, to improve its second-order optical nonlinear coefficient，keeping its good physical and chemical characters in the same time，a new SFD crystal Nd3+:YCa9(V1-xNbxO4)7 will be acquired.. By studying the relationships of the structure and the Second harmonic generation, the operating mechanism can be achieved, which will be useful in the research of the other SFD crystals. .By using the innovative methods as follows: adopting liquid synthesis method to synthesize the growing raw material, designing special temperature field of the furnace, using different atmosphere in different growing period, annealing in special program, adding alterable oxide into the growing melt, a new bulk SFD crystal of Nd3+:YCa9(V1-xNbxO4)7 with big dimensions and good optical quality can be obtained. After measuring its parameters, the laser experiment will be carried out, the SFD green and blue laser with W and mW level can be achieved. Then, a new self-frequency-doubling crystal which produces green and blue laser can be obtained, and it may has huge economic value.

全固态蓝绿光激光器由于体积小、易调整、稳定性高，获得了广泛的应用。采用自倍频技术获得蓝绿光有独特优势，其核心是自倍频晶体，但目前尚无理想的成熟产品。采用结构调控方法，在Nd:YCa9(VO4)7中加入Nb离子，增加基团微观二级极化率，在保持其各种良好物化性能的同时，有望大幅提高其倍频系数，获得一种新的自倍频晶体Nd:YCa9(V1-xNbxO4)7。研究其结构和非线性性能关系，获得机理，为相关晶体的研制提供指导。采取液相合成原料、独特的炉体温场设计、分阶段控制生长气氛、多阶段退火、在熔体中加入微量变价氧化物等创新性方法，使用提拉法生长出光学质量优异、大尺寸的Nd:YCa9(V1-xNbxO4)7晶体。测定各种参数，进行激光实验，获得大于W级和毫W级的自倍频绿、蓝光输出，得到一种新的、实用的激光自倍频晶体。

自倍频激光晶体材料是产生蓝绿激光的有效手段，目前缺少能产生高效率大功率自倍频激光输出的材料，该研究具有较大的社会效益和经济价值。通过本项目的研究，明确了Nb掺杂对YCa9(VO4)7结构有着明显的影响，通过使VO4基团发生畸变，大幅提高了其有效倍频系数，得到了倍频系数约5.6倍KDP的YCa9(V0.96Nb0.04O4)7化合物，获得了结构和性能的关系，该结果有望应用于其它相关晶体材料的研究中，提供有价值的借鉴；通过改进生长条件，生长出尺寸大于25×30 mm3、可见近红外波段光学透过率大于75%的Nd3+:YCa9(V0.96Nb0.04O4)7晶体，获得其详细的物化性质和光谱性质，进行了相应的理论计算；进行了激光实验，采用LD泵浦，获得了0.25W、波长1.08μm的准连续激光输出，其斜效率约为9%；获得了一系列同结构类型的该类晶体，研究结果显示这些晶体均具有较好的综合性能，可望用于产生新波段激光和自倍频激光领域中；发现了一种新的倍频晶体CaSrNb2O7，用提拉法生长出了单晶，此晶体属于正交晶系，晶胞参数为a=3.913 Å，b=26.667 Å，c=5.626 Å， Z=4， Cmc21 空间群，该晶体的紫外吸收截止边在370 nm处，在可见及近红外的的透过率达80%，其SHG强度大约是KDP晶体的3-4倍，能够实现相位匹配，可掺入稀土激活离子，是一种潜在的自倍频激光晶体材料。. 项目基本达到了的研究目标。共发表了基金标注的论文21篇，其中第1标注的论文12篇，第2标注的论文4篇，申请中国发明专利2件。培养毕业博士1名，毕业硕士4名，其中一人获国家奖学金。