基于强场耦合效应实现2微米超快激光输出的硅酸盐晶体研究

The research on ultrafast laser is moving forward from around 1μm near infrared to 2μm mid-infrared region now. Ultrafast laser around 2μm region has potential applications in light detection and ranging (LIDAR), image and laser microsurgery, etc. Tm3+-Ho3+ co-doped crystalline hosts are the most important..This project focuses on the Tm3+-Ho3+ co-doped single and mixed oxyorthosilicate crystals Tm,Ho:Re2SiO5，by structure design and adjust of Re=Gd,Lu,Y,Sc cetc. The main contents of this project are listed as follow: 1) realizing Tm/Ho laser output with high efficiency, low threshold, low temperature effects by creating strong local crystal-field result in large crystal-field splitting. 2)obtaining ultrafast laser host with wide smooth and high gain fluorescence around 1.9-2.1μm by forming of lattice disorder and multisites of Tm/Ho ions. We will develop valuable ultrafast lasers around 2μm region with independent intellectual property rights.

超快激光正在从近红外1μm波段向中红外2μm波段拓展，2μm波段超快激光在测距、雷达、遥感、成像和外科手术(医疗)等领域具有潜在的应用。Tm/Ho共掺的激光晶体是主要发展方向。.本项目拟选择稀土正硅酸盐（Tm,Ho:Re2SiO5，Re=Gd，Lu，Y，Sc等）单晶及其混晶为主要研究对象，通过分子设计、Re=Gd，Lu，Y，Sc等的组合和调控：1）进一步提高晶体中Tm3+/Ho3+激活离子和基质的耦合强度，实现弱温度效应、低阈值的强场耦合准四能级激光运转；2）在基质晶体中形成无序（Disorder）和多格位（Multisites），获得具有平滑宽发射带和高增益的1.9-2.1μm波段宽调谐超快激光介质。该研究对我国发展具有自主知识产权的高效率、低阈值全固态2μm中红外波段超快激光具有重要的现实意义。

生长出大直径、高光学质量的掺Tm/Ho硅酸盐晶体；获得最佳Tm3+、Ho3+浓度配比和偏振方向。LD泵浦 Tm:SSO实现1971nm波长激光输出，最高输出功率934mW，斜效率25.9%。LD泵浦Tm:YSO实现1969.8nm波长3.23W连续激光输出，斜率效率34.3%，并分别实现了1976nm、1972.9nm、2044.6nm不同波长激光输出，并采用Cr:ZnSe做可饱和吸收体在1944nm、2022nm成功实现调Q激光输出，平均功率0.74W、78.3ns。LD泵浦 Tm:SYSO实现2022nm波长激光输出，输出功率580mW，斜效率17.4%，可实现1950~2057nm可调谐激光输出。并实现2010nm和2023nm双波长激光输出。