LEAPS-MPS: Exploring Thiophosphates as Balanced Middle-infrared Nonlinear Optical Materials

非技术总结当你在超市等待结账时，你有没有想过工作人员怎么能这么快地扫描所有东西？“叮当”，一声完了。“叮当”，又一次成功了！你需要印在商品上的条形码和红外激光扫描仪！这并不是我们日常生活中使用的唯一红外激光的例子！除了我们的日常生活之外，红外激光器还在仪器光谱、光学传感、光学成像和远程通信等方面有各种重要的应用。要产生红外激光，一种关键而实用的方法是通过非线性谐波产生过程，即两个或多个光子合并在一起。将非线性谐波产生过程引入到固体激光系统中，具有紧凑、高效和可靠的特点。非线性谐波产生过程的核心是红外非线性光学材料。在MPS-LEAPS奖项的支持下，这位来自威奇托州立大学的首席研究员利用用于IR NLO应用的新兴无机化合物的设计、合成、发现、优化和晶体生长，该奖项部分由既定的刺激竞争研究计划(EPSCoR)资助。因此，新发现的材料有望用于产生红外激光。该奖项的教育努力是通过开发水晶博物馆、多样化招聘、发展新班级以及向小学推广活动，将研究纳入无机化学教学和推广活动。PI通过雇佣女性研究人员、非裔美国学生、第一代大学生和其他在科学领域未被充分代表的群体来建立一支多元化的团队。技术摘要中红外非线性光学材料(MIR NLO)因其能够通过二次谐波产生过程扩展红外激光频率而引起越来越多的兴趣。这项研究项目得到了MPS-LEAPS奖的支持，重点是使用各种合成方法，通过不同的策略实现平衡的NLO性能，通过TB-LMTO-ASA模拟了解电子结构和成键特性，以及生长大晶体。这项拟议的研究促进了对硫代磷酸盐等无机化合物结构与性质关系的理解，并揭示了有前景的MIR NLO材料。硫代磷酸盐是一类结合硫和磷的物质。PI和他的研究小组致力于将硫代磷酸盐作为MIR NLO材料的探索，旨在取代目前的MIR NLO材料。目前的MIR非线性光学材料具有较低的激光损伤阈值和适度的转换效率。开发的新材料被用来产生新的中红外激光频率，这使得在化学、生物和物理等领域进行广泛的光谱研究成为可能。通过原位粉末X射线结合差示扫描量热测试来了解晶体生长过程所采用的方法缩短了新相晶体生长的“试错”过程。了解电子结构如何影响光学性质，以及几何、拓扑和缺陷如何影响电子结构，有助于构建有前途的功能材料，如量子材料、热电材料等。PI和他的研究小组的长期教育目标是将研究纳入无机化学教学，增加PI研究团队的多样性和包容性，增加公众对化学的参与，培养下一代化学家，并支持STEM中代表不足的少数群体的学生。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-Technical SummaryWhen you wait to check out in a supermarket, do you ever wonder how the staff can scan everything so fast? 'Ding', one done. 'Ding', another done! You need barcodes printed on items and an infrared laser scanner! This is not the only example of infrared lasers used in our daily life! In addition to our daily life, infrared lasers have various important applications such as instrumental spectroscopy, optical sensing, optical imaging, and long-distance communications. To generate infrared lasers, one crucial and applicable way is via the nonlinear harmonic generation process, where two or more photons are merged together. The nonlinear harmonic generation process is incorporated into solid-state laser systems, which are compact, highly efficient, and reliable. The heart of the nonlinear harmonic generation process is the infrared nonlinear optical (IR NLO) material. With support through an MPS-LEAPS award, which is in part funded by the Established Program to Stimulate Competitive Research (EPSCoR), the principal investigator from Wichita State University employs the design, synthesis, discovery, optimization, and crystal growth of emerging inorganic compounds for IR NLO applications. Thus newly discovered materials are expected to be useful to generate IR lasers. The educational efforts of the award are to incorporate research into inorganic chemistry teaching and outreach activities via the development of a crystal museum, diverse hiring, development of a new class, and outreach activities to elementary schools. The PI builds a diverse team by hiring women researchers, African-American students, first generation college students, and other groups underrepresented in scientific fields.Technical SummaryMiddle Infrared nonlinear optical materials (MIR NLO) have sparked growing interest due to their capability to extend infrared laser frequencies via the second harmonic generation process. This research project, supported by an MPS-LEAPS award, emphasizes employing various synthetic methods, achieving balanced NLO properties via different strategies, understanding electronic structures and bonding characteristics via TB-LMTO-ASA simulations, and growing large crystals. The proposed research advances the understanding of the structure-property relationships of inorganic compounds such as thiophosphates and uncovers promising MIR NLO materials. Thiophosphates are a class of materials combining sulfur and phosphorus. The PI and his research group tackle the exploration of thiophosphates as MIR NLO materials, which are aimed to replace current MIR NLO materials. Current MIR NLO materials have low laser damage thresholds and modest conversion efficiencies. The developed new materials are utilized to produce new frequencies of mid-IR lasers, which enables a wide range of spectroscopic studies in chemistry, biology, and physics, etc. The employed methodology of understanding crystal growth processes via in-situ powder X-ray coupled with differential scanning calorimetry tests shortens the “trial and error” process of crystal growth of new phases. Understanding how the electronic structure influences optical properties, and how geometry, topology, and defects affect electronic structure, helps build promising functional materials such as quantum materials, thermoelectric materials, etc. The long-term educational goal for the PI and his research group is to incorporate research into inorganic chemistry teaching, increase the diversity and inclusion of the PI’s research team, increase public engagement of chemistry, train next generation chemists, and support students from minority groups underrepresented in STEM.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.