Crystal-Field Engineering of Transition Metal Doped Chalcogenide Laser Materials

该项目致力于过渡金属(TM)掺杂II-VI半导体的新型掺杂剂-基质组合，以扩展当前的固态激光波长覆盖范围。材料包括Tm(Cr，Fe，Co)掺杂的Cd_(1-x)RxTe，R为IIa(Be，Mg，Ca，Sr，Ba)或IIb(Zn，Hg)元素。为了改变晶场对Tm离子的光学和激光性质的影响，将改变基质的组成。提议的材料将由汉普顿大学的布里奇曼技术公司种植，并将与美国布里姆罗斯公司的工业合作伙伴合作提供额外的样本。所有材料都将通过随温度变化的透射谱、稳态和时间分辨发射研究以及激光性能研究进行表征。光谱结果将在晶场理论的框架内模拟，以求出晶场参数、电子-声子耦合强度和发射猝灭激活能。建模的结果将被用于推导结构-性能关系，从而指导所选材料的优化以获得更好的激光性能。该项目涉及与具有技术相关性的电子/光子材料有关的基础研究问题。该项目的多学科性质提高了汉普顿大学几个科学和工程学科的教育质量。这项研究将纳入对寻求物理、化学、化学工程和电气工程学位的学生的培训。教育努力包括：(1)增加学生参与研究项目，(2)继续和扩大工业实习计划，以及(3)外展活动。这一方案预计将增加光电子和激光这一重要领域的熟练劳动力，特别强调加强代表人数不足的少数群体的参与。

This project addresses new dopant-host combinations of transition metal (TM) doped II-VI semi-conductors to extend current solid-state laser wavelength coverage. Materials include TM (Cr, Fe, Co) doped Cd1-xRxTe, with R being either a IIa (Be, Mg, Ca, Sr, Ba) or IIb (Zn, Hg) ele-ment. The composition of the host will be varied in order to modify crystal-field effects on opti-cal and laser properties of TM ions. The proposed materials will be grown by a Bridgman tech-nique at Hampton University, and collaboration with industrial partners at Brimrose Corporation of America will provide additional samples. All materials will be characterized through tempera-ture dependent transmission spectroscopy, steady-state and time-resolved emission studies, and laser performance studies. The spectroscopic results will be modeled within the framework of crystal field theory to derive crystal-field parameters, electron-phonon coupling strengths, and emission quenching activation energies. The results of the modeling will be used to derive struc-ture- property relations, which can guide the optimization of selected materials to achieve better laser performance. The project addresses fundamental research issues associated with electronic/photonic materials having technological relevance. The multi-disciplinary nature of the project enhances the quality of education in several science and engineering disciplines at Hampton University. The research will be incorporated in the training of students seeking degrees in physics, chemis-try, chemical engineering, and electrical engineering. Educational efforts include: (1) increase of students participating in research projects, (2) continuation and extension of an industrial intern-ship program, and (3) outreach activities. This program is expected to increase the skilled work-force in an important field of optoelectronics and lasers with a special emphasis on enhancing the participation of under-represented minorities.