SBIR Phase I: Ytterbium-Doped Stoichiometric Lithium Niobate for Self-Frequency Conversion Lasers

这个小企业创新研究（SBIR）第一阶段项目将展示基于掺镱铌酸锂（SLN）晶体的新型激光辐射源的潜力。掺镱SLN晶体将同时用作激光器和非线性变频器，使其能够在一个简单、紧凑的设备中产生广泛的波长范围。作为一种有源激光离子，Yb具有二极管抽运效率高、热负荷低、对激光辐射重吸收小等优点。这种激光辐射可以通过非线性光学效应转换为各种感兴趣的波长，这是铌酸锂固有的。铌酸锂准相位匹配技术的最新发展增加了非线性光学频率转换产生的效率和波长范围。化学计量铌酸锂的使用比传统的全等铌酸锂更容易通过电场极化制造准相匹配结构，并且具有更高的功率处理能力。Yb激光、准相位匹配频率转换以及单晶SLN的制造和功率处理的综合优势将使目前无法获得的波长的新激光辐射源得以实现。这将使新型激光器具有重量轻、结构紧凑、操作效率高、光谱通用性强等特点。商业应用包括开发用于非实验室环境的眼睛安全激光器，如测距仪、激光测量和测绘以及污染监测。重要的医疗应用也可能存在。

This Small Business Innovative Research (SBIR) Phase I project will demonstrate the potential of new sources of laser radiation based on ytterbium (Yb) doped stoichiometric lithium niobate (SLN) crystals. The Yb-doped SLN crystal will serve as both the laser and nonlinear frequency converter to enable the production of a broad range of wavelengths in a simple, compact device. As an active lasing ion, Yb has the advantages of efficient diode pumping, low thermal loading, and minimal reabsorption of laser radiation. This laser radiation can be converted to various wavelengths of interest via nonlinear optical effects that are intrinsic to lithium niobate. Recent developments in quasi-phase matching techniques in lithium niobate have increased both the efficiency and range of wavelengths that can be generated by nonlinear optical frequency conversion. The use of stoichiometric lithium niobate over conventional congruent lithium niobate leads to greater ease in fabrication of quasi-phase matched structures via electric field poling, and higher power handling capabilities. The combined advantages of Yb lasing, quasi-phase matched frequency conversion, and fabrication and power handling of SLN in one single crystal will enable the realization of new sources of laser radiation at wavelengths not currently available. This will make possible new lasers characterized by lightweight, compact construction, efficient operation, and spectral versatility. Commercial applications include the development of eye safe lasers for non-laboratory environments such as range finders, laser surveying and mapping, and pollution monitoring. Significant medical applications also may exist.