激光陶瓷材料单晶化机理研究

Focusing on the waste heat of high power pump process is easy to cause composite laser bonding surface cracking， laser threshold increasing and the slope efficiency decreasing, we development the mechanism research on solid-state single crystal growth (SSCG) of laser ceramics. The original bond surface was eliminated by high temperature inducing ceramic directed growth, which can further optimize the interface behavior of composite laser materials, implement effective thermal control. We study on the mechanism of single crystal induced ceramic orientation growth under high-temperature sintering process, meanwhile, we systematically studied the influence mechanism of different experimental parameters on crystallization speed of SSCG and the effect of the SSCG process on the micro-pore elimination in ceramics, finally obtain ceramic monocrystal integration and high doping laser ceramics/single crystal composite materials. Develop the design method, theory and preparation method of ceramic/single crystal composite laser gain medium with independent intellectual property right, and lay the material foundation for high power solid laser.

针对高功率激光工作过程中废热导致的材料开裂、激光阈值升高、斜效率降低等问题，创新性地开展高温单晶诱导陶瓷定向生长（激光陶瓷材料单晶化）机理研究。通过高温诱导陶瓷定向生长消除原有键合面，优化激光材料复合结构的界面行为，实现有效热管控。对高温烧结过程中单晶诱导陶瓷定向生长机理进行研究，系统研究诱导温度、烧结时间、陶瓷晶粒大小以及抛光质量对陶瓷单晶化速度及陶瓷内微气孔排除影响机理，最终获得陶瓷单晶一体化、芯层掺杂浓度高的新型激光陶瓷/单晶复合材料，发展具有自主知识产权的适用于不同场景的陶瓷/单晶复合激光增益介质的设计方法、理论和制备方法，为高功率固体激光奠定材料基础。

采用新型的陶瓷单晶化工艺，通过高温诱导单晶向陶瓷内定向生长，使得平面波导的芯层和包层生长成为一体，极大提升了平面波导的机械强度，改善了热管理性能。利用YAG陶瓷粉末包埋YAG籽晶制备出复合样品，对陶瓷单晶化过程中的影响因素、生长机理进行了研究，通过OR生长机制动力学LSW模型解释该过程并确定了生长模型；利用低温真空预烧和热等静压两步烧结法制备YAG单晶/YAG陶瓷复合结构，从理论上解决单晶化初始温度过高导致的界面处的气孔残余问题，最终获得透过率83.7%、单晶生长厚度为200微米、无键合面的高质量平面波导结构，烧结时间缩短至传统工艺的1/6；通过制备钕掺杂陶瓷的复合样品，对陶瓷单晶化过程中离子的分凝现象和扩散现象进行了研究，实验验证了6%重掺Nd: YAG生长单晶层方案的可行性；最终制备出的YAG/Yb：YAG/YAG波导试样斜率效率达60%，光束质量在X和Y方向分别为1.1和2.1，达到预期研究目标。