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

0245455Ganem拟议的研究是关于Tu敏化的氯化钾铅钾KPb2C15激光晶体。研究将包括合成这些材料，并使用吸收和激光诱导荧光技术进行光谱分析。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掺杂稀土离子时，降低的声子能量使有用的红外荧光跃迁成为可能，而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，因此它在开发坚固耐用、高功率、固态稀土基红外激光器方面具有广阔的前景。Tu被广泛用于敏化低成本800 nm二极管泵浦的红外激光器。到目前为止，还没有关于Tu在KPb2C15中的使用的研究。这项研究将测量稀土离子Pr3+和Er3+共掺到KPb2C15中对Tu的吸收、发射和能量转移。建议研究的智慧价值：近年来，人们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。长波长电子跃迁更有可能在氯化物中辐射，因为降低的声子能量抑制了多声子弛豫。最近的一些例子：LaC13中基于Pr3+的激光器工作在1.7、5.2和7.2um，最后一个转变是在室温下工作的。LaCl3仍然存在极度湿气敏感和机械不稳定的问题，并限制了这些设备的实用性。使用KPb2C15，这项建议的主题，是有价值的，因为它是一种机械稳定的氯离子晶体，将使实用的氯基红外激光的开发成为可能。作为我目前NSF拨款的一部分，我们已经展示了使用KPb2C15的室温二极管泵浦的4.6微米Er~(3+)激光器。拟议的工作是改进Er3+激光和Pr3+激光与Tm3+敏化。拟议的研究的广泛影响：拟议的研究将影响教育项目和重要的技术领域。技术影响将发生在美国政府特别感兴趣的两个领域。-遥感-截至撰写本文时，能源部(DOE)通过其国防核不扩散办公室(NN)正在为一项SBIR提案提供资金，以开发包括KPb2C15在内的低声子能量材料，这是为用于国家安全应用的传感器的支持技术提供资金的计划的一部分。-红外对抗(IRCM)发展掺铒KPb2C15激光器的一个动机是为了红外对抗。4.6微米的工作波长非常适合IRCM，因为它位于4到5微米之间的大气传输窗口。IRCM申请的重要性促使海军资助了一项生长稀土掺杂KPb2C15的SBIR第一阶段合同。Th掺杂KPb2C15是合同公司没有积极探索的研究领域，但他们感兴趣的是这种材料的潜在市场。RUI Impact声明中描述的这项RI计划(在本科生机构进行研究)的教育影响包括：本科生参与，与其他学校(包括K-12城市学校和一所女子学院)的接触，以及教学与研究一体化。

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.