RUI: Synthesis and Optical Spectroscopy of Thulium Sensitized Potassium Lead Chloride Laser Materials

本文拟研究的是铥敏化氯化铅钾KPb2C15激光晶体。研究将包括合成这些材料和使用吸收和激光诱导荧光技术进行光谱学。KPb2C15晶体主体是一种既具有机械稳定性又具有低声子能量的材料。当KPb2C15中掺杂稀土离子时，减少的声子能量能够实现有用的红外荧光跃迁，这在传统的氧化物或氟化物激光晶体中是不存在的。由于它是一种机械稳定的低声子能量晶体，它显示出开发坚固耐用、高功率、固态稀土红外激光器的希望。铥被广泛应用于红外激光器的致敏，用于低成本的800纳米二极管泵浦。到目前为止，还没有关于在KPb2C15中使用铥的研究。本研究将测量铥对共掺杂到KPb2C15中的稀土离子Pr 3+和Er 3+的吸收、发射和能量转移。建议研究的知识价值：近年来，对低声子能量激光材料，特别是氯化物晶体的兴趣显著增加。长波长电子跃迁更可能在氯离子中辐射，因为减少的声子能量抑制了多声子弛豫。最近的一些例子：基于pr3 +的激光器在LaC13中工作在1.7,5.2和7.2 um，最后一个转变在室温下工作。LaCl3的极端湿度敏感性和机械不稳定性问题仍然存在，并限制了这些设备的实用性。KPb2C15是一种机械稳定的氯化物晶体，它的优点是可以开发出实用的氯化物基红外激光器。作为我目前在NSF资助下工作的一部分，我们已经展示了使用KPb2C15的室温二极管泵浦4.6 um Er 3+激光器。提出的工作是改进er3 +激光器和pr3 +激光器的Tm 3+敏化。拟议研究的广泛影响：拟议的研究将影响教育计划和重要的技术领域。技术影响将发生在美国政府特别感兴趣的两个领域。-遥感-在撰写本文时，能源部（DOE）通过其国防核不扩散办公室（NN）正在资助SBIR的一项提案，以开发包括KPb2C15在内的低声子能量材料，作为资助用于国家安全应用的传感器支持技术的计划的一部分。红外对抗（IRCM）研制掺铒KPb2C15激光器的动机之一就是红外对抗（IRCM）。4.6微米的工作波长非常适合IRCM，因为它落在4到5微米之间的大气传输窗口。IRCM应用的重要性促使海军资助了稀土掺杂KPb2C15的第一阶段SBIR合同。掺杂铥的KPb2C15是一个研究领域，合同下的公司没有积极探索，但它们对此很感兴趣，因为它有可能扩大该材料的市场。在RUI影响声明中描述了该RUI提案（本科院校研究）的教育影响，包括：本科生参与，向其他学校（包括城市K-12学校和一所全女子学院）的推广以及教研整合。

0245455GanemThe proposed research is on thulium-sensitized potassium lead chloride KPb2C15 laser crystals. Research will include synthesizing these materials and performing optical spectroscopy using absorption and laser-induced fluorescence techniques. The KPb2C15 crystalline host is a material that has both mechanical stability and low-phonon energies. When KPb2C15 is doped with rare earth ions, the reduced phonon energies enable useful infrared fluorescence transitions that would be absent in traditional oxide or fluoride laser crystals. Since it is a mechanically stable low-phonon energy crystal, it shows promise for the development of rugged, durable, high-powered, solid-state rare earth-based infrared lasers. Thulium is widely used to sensitize infrared lasers for pumping with low-cost 800 nm diodes. To date no studies of the use of thulium in KPb2C15 have been conducted. The research will measure thulium absorption, emission, and energy transfer to the rare earth ions Pr 3+ and Er 3+ co-doped into KPb2C15.Intellectual Merit of Proposed Research:Interest in low-phonon energy laser materials, especially chloride crystals, has increased significantly in recent years. Long-wavelength electronic transitions are more likely to radiate in a chloride host because the reduced phonon energies inhibit multi-phonon relaxation. Some recent examples: Lasers based on Pr 3+ in LaC13 have been operated at 1.7, 5.2 and 7.2 um with this last transition operating at room temperature. The problem of extreme moisture sensitivity and mechanical instability remains for LaCl3 and has limited the practicality of these devices. The use of KPb2C15, the subject of this proposal, is of merit because it is a mechanically stable chloride crystal and will make possible the development of practical chloride-based infrared lasers. As part of the work under my current NSF grant, we have demonstrated a room temperature diode-pumped 4.6 um Er 3+ laser using KPb2C15. The proposed work is to improve both the Er 3+ laser and Pr 3+ lasers with Tm 3+ sensitization.Broad Impacts of Proposed Research:The proposed research will impact both education programs and vital areas of technology. The technological impact will occur in two areas of special interest to the United States government. - Remote sensing- As of this writing, the Department of Energy (DOE), through its Office of Defense Nuclear Nonproliferation (NN), is funding an SBIR proposal to develop low-phonon energy materials, including KPb2C15, as part of a program to fund support technologies for sensors used in national security applications. - Infrared countermeasures (IRCM) One motivation for developing the erbium-doped KPb2C15 laser is for IRCM. The 4.6 micron operating wavelength is ideally suited for IRCM since it falls in an atmospheric transmission window between 4 and 5 microns. The significance of the IRCM applications has motivated the Navy to fund a Phase I SBIR contract for the growth of rare earth doped KPb2C15.Thulium-doped KPb2C15 is an area of research not under active exploration by the companies under contract, however it is of interest to them because of the potential to expand the market for the material.The educational impact of this RUI proposal (Research at Undergraduate Institutions), described in the RUI impact statement, includes: undergraduate participation, outreach to other schools (including urban K-12 schools and an all women college) and teaching-research integration.