Professor of Physics B.S. 1986, University of Oldenburg, Germany M.S. 1990, University of Oldenburg, Germany Ph.D. 1994, University of Hamburg, Germany Room 102 Olin Engineering Building Phone: 757.727.5829 Fax: 757.728.6910 Email: uwe.hommerich@hamptonu.edu

Research Interests: Luminescent Materials Development, Laser Spectroscopy, Crystal Growth

     The research of my group focuses on the development and characterization of new luminescent materials which are of interest for applications such as light emitting diodes, solid-state lasers, optical amplifiers, and phosphor materials. The advancement of luminescent materials requires a detailed understanding of their properties so that material preparation can be optimized and creative solutions to current limitations can be found.  State-of-the-art laser facilities are being employed by us to perform comprehensive optical characterization and device testing of new materials.  Material synthesis is being carried out at Hampton University and in cooperative research programs with universities and industry.

At present, we are interested in the optical properties of rare earth and/or transition metal ion doped solids for applications as solid-state laser materials and phosphors. A current direction of our research focuses on the study of rare earth ions (Er3+, Eu3+, etc.) in wide-gap semiconductor hosts (e.g. AlN, GaN) with the goal of combining the favorable luminescence properties of rare earth ions with the electronic properties of semiconductors. Highly efficient and compact opto-electronic devices for applications in optical communication and display technology are envisioned in the near future. We are also investigating the infrared emission properties of rare earth doped low-phonon energy hosts, e.g. halides and chalcogenides. The non-radiative decay rates of rare earth ions are greatly reduced in low-phonon host materials, which can result in efficient infrared emission at room-temperature. Recently, we demonstrated efficient mid-infrared emission in the technologically important 3-5 micron region from several rare earth doped potassium lead halide crystals.

In teaching, I emphasize the close relations between experiment, theory, and applications of physics. I stress in my classroom, that many technological developments are based on fundamental concepts and principles in physics. I introduce new physical concepts by explaining several of their applications or by using classroom demonstrations and audio-visual equipment. Moreover, I aim to combine lecturing with project-oriented learning and hands-on experimentation.

Selected Publications:

• E. Brown, U. Hömmerich, A. G. Bluiett, S. B. Trivedi, J. M. Zavada, “Synthesis and Spectroscopic Properties of Neodymium doped Lead Chloride”, Journal of Applied Physics, 101 (2007) 113103.
• C.S-C. Yang, E. Brown, U. Hommerich, S. B. Trivedi, A. P. Snyder, A. C. Samuels, “Mid-Infrared Emission from Laser-induced Breakdown Processes”, Applied Spectroscopy, 61 (2007) 321.
• U. Hömmerich, E. Brown, P. Amedzake, S. B. Trivedi, J. M. Zavada, “Mid-infrared emission properties of Pr3+ doped KPb2Br5”, Journal of Applied Physics, 100 (2006) 113507.
• U. Hömmerich, E. Brown, S. B. Trivedi, J. M. Zavada, “Synthesis and 1.5um Emission Properties of Nd3+ activated Lead Bromide and Lead Iodide Crystals”, Applied Physics Letters, 88 (2006) 251906.
• U. Hömmerich, J. A. Freeman, EiEi Nyein, S. B. Trivedi, J. M. Zavada, “Crystal Growth and Infrared Emission of Dy doped Potassium Lead Bromide”, Journal of Crystal Growth, 287 (2006) 230