钬激光器双波长同带泵浦及双增益光谱平坦技术研究

Ho laser materials have many enough energy levels. For example, there are 192 potential transitions between the Stark split levels of 5I7 and 5I8 manifold. These transitions form the wide absorption and emission band of Ho:YAG. All of these show us the fascinating complexity of Ho transitions. But it also leads to the wavelength unstable when a Ho laser operates under different conditions and draw back application. There is still no systematic theoretical to explain the transitions of Ho laser materials. In this project, a narrow- and dual-wavelength Tm fiber will be used as an in-band-pump source each of which can be independently tuned to match the absorption peaks of a Ho laser material. The transition rules between the Stark levels of 5I7 and 5I8 manifold will be investigated to find out the mechanism of coupling effect between the absorption and emission transitions. It will assist us to find out the theory and technical routine of achieving a stable wavelength Ho laser, spectra flattening technology with double gain materials and building a dual-gain ultrashort pulse Ho solid laser. Our team have a wealth of experience on Ho solid state lasers pumped by a Tm fiber and the mid-infrared laser technology will be improved rapidly when the new technology breakthroughs of a Ho laser is achieved.

Ho激光材料拥有丰富的能级系统，以Ho:YAG为例，其5I7和5I8激光主带Stark子能级间拥有192个潜在跃迁波长，构筑了其较宽的吸收和发射谱带，显现出迷人的复杂性；但也致使在不同运转条件下，Ho激光器呈现出显著的频率不稳定性，给应用带来不便。Ho激光材料的跃迁规律目前仍然缺少系统的理论支撑。本项目将以自建的高功率、窄线宽、波长可独立调谐的双波长掺铥光纤激光器作为特种泵浦源，采用同带泵浦技术方式，精确匹配Ho:YAG等激光介质的吸收峰；系统研究激光振荡规律，探索Ho材料5I7和5I8激光主带Stark子能级间吸收与发射跃迁的相互耦合影响机理，为实现Ho激光波长稳定输出、探索双增益材料光谱平坦技术以及研发新型双增益材料超短脉冲Ho固体激光器寻求理论基础和技术路线。项目组在Tm光纤同带泵浦Ho固体激光器研究方面具有丰富经验，如能实现Ho激光产生新技术突破，将极大推动中红外激光技术的快速发展

Ho激光材料拥有丰富的能级系统，构筑了其较宽的吸收和发射谱带；Ho激光器呈现出显著的频率不稳定性，给应用带来不便。Ho激光材料的跃迁规律目前仍然缺少系统的理论支撑。本项目将以自建的高功率、窄线宽、波长可独立调谐的双波长掺铥光纤激光器作为特种泵浦源，采用同带泵浦技术方式，探索Ho材料5I7和5I8激光主带Stark子能级间吸收与发射跃迁的相互耦合影响机理，为实现Ho激光波长稳定输出寻求理论基础和技术路线。.1..采用自主专利技术，使用双VBG对Tm光纤激光器进行波长调节，可以实现双波长输出，作为Ho激光器的双波长泵浦源；采购了窄带宽1.9微米波长半导体激光器，搭建了Tm光纤激光器和半导体激光器混合泵浦源。.2..在详细研究Ho:LuAG激光材料的基础上，进一步分析了理论分析了Ho:YAG材料的能级系统，比较了Ho:YAG和Ho:LuAG在激光运转跃迁循环上的差异以及激光运转受温度影响的程度差异。.3..研究了YAG、Y2O3等体系透明陶瓷的各类制备工艺，并研究了晶粒、晶界等微结构以及氧空位对激光陶瓷的光学属性影响。..本项目共发表论文16篇，申请专利3项。.