Contact

Location:
Room 102 Olin Engineering Building

Phone:
757.727.5829

Fax:
757.728.6910

Uwe Hömmerich

Position:
Professor of Physics

Educational Background:
B.S. 1986, University of Oldenburg, Germany
M.S. 1990, University of Oldenburg, Germany
Ph.D. 1994, University of Hamburg, Germany
(in collaboration with the University of Georgia, Athens, USA)

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 in solid-state lasers, optical amplifiers, light emitting diodes, and phosphors. 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 doped bulk and nano-crystalline materials for photonic applications. For example, a current focus of my research group is the infrared optical properties of rare earth doped low-phonon energy halide crystals for applications as mid-infrared gain media. 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. Jointly with our collaborators, we demonstrated efficient mid-infrared emission in the technologically important 3-5 mm region from several rare earth doped potassium lead halide crystals.

More recently, we started a project on infrared laser-induced breakdown spectroscopy (IR-LIBS) for applications in biological and chemical sensing. Jointly with researchers at Brimrose Corporation of America and Edgewood Chemical Biological Center, we demonstarted the first observation of IR LIBS emission signatures in the 3-5 mm region from carbon containing materials, alkali halides, and ammonium compounds. Detailed studies of IR LIBS for applications in environmental monitoring, geological sciences, pharmaceutical industry, monitoring of industrial processes, and homeland security are still in progress.

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:

C. Hanley, E. Brown, U. Hömmerich, S. Trivedi, J.M. Zavada, "Spectroscopic studies of the 1.5 µm emission from polycrystalline ceramic Er: YAG and Er: KPb2Cl5", Journal of Alloys and Compounds, 488, 624 (2009).
E. Brown, O. Oyebola, U. Hömmerich, T. Yamada, H. Yamane, J.M. Zavada, "Spectroscopic characterization of Praseodymium doped Gallium Nitride powder prepared by a Na flux method", Journal of Alloys and Compounds, 488, 628 (2009).
C.S-C. Yang, E. Brown, U. Hömmerich, S. B. Trivedi, A. C. Samuels, A. P. Snyder "Mid-Infrared Laser-induced Breakdown Spectroscopy Emission from Alkali Metal-Halides", Applied Spectroscopy, 62, 714 (2008).
P. Amedzake, E. Brown, U. Hömmerich, S. B. Trivedi, J. M. Zavada, "Crystal Growth and Spectroscopic Characterization of Pr-doped KPb2Cl5 for Mid-Infrared Laser Applications", Journal of Crystal Growth, 310, 2015 (2008).
E. Brown, U. Hömmerich, S. B. Trivedi, J.M. Zavada, "Mid-infrared emission properties of Nd doped lead halides for photonic applications", Materials Science and Engineering B, 146, 103 (2008).
A. G. Bluiett, E. Brown, U. Hömmerich, J. M. Zavada, "Energy transfer processes in doubly doped Yb,Pr: KPb2Cl5 for mid-infrared laser applications", Materials Science and Engineering B, 146, 110 (2008).
S. B. Trivedi, C.C.Wang, S. Kutcher, U. Hömmerich, W. Palosz, "Crystal Growth Technology of Binary and Ternary II-VI Semiconductors for Photonic Applications", Journal of Crystal Growth, 310, 1099 (2008).
S. B. Trivedi, C.C.Wang, S. Kutcher, U. Hömmerich, W. Palosz, "Crystal Growth Technology of Binary and Ternary II-VI Semiconductors for Photonic Applications", Journal of Crystal Growth, 310, 1099 (2008).
C.S-C. Yang, E. Brown, U. Hömmerich, S. B. Trivedi, A. P. Snyder, A. C. Samuels, "Mid-Infrared Emission from Laser-induced Breakdown Processes", Applied Spectroscopy, 61 321 (2007).
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, 113507 (2006)
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, 230 (2006).