Following its discovery at U-M in 2007, the main topic of research in Professor Rand's group is optical magnetism. Intense magnetization has been induced experimentally in a variety of transparent insulating materials by light at moderate intensities and for the first time provides a direct way to control spins in dielectric condensed matter, to separate charges for optical-electrical power conversion, and to modify the permeability of natural materials for transformation optics. Quantum theory of this unexpected phenomenon was recently published, explaining how parametric enhancement of the weak magnetic force of light leads to previously unknown magneto-electric effects under non-relativistic conditions.
Experiments on this and other topics in Professor Rand's laboratory emphasize high resolution laser spectroscopy of solids. Ultrashort pulse lasers and tunable continuous sources are the main tools used to make time-resolved and frequency-resolved measurements in new materials such as sesquioxide powders, transparent ceramics, and hybrid polymers in order to evaluate their structure-function relationships and their suitability for applications. These classes of materials are relevant both to magnetic optics and other subjects of current interest in the group, such as random lasers, wide bandwidth ceramic lasers, and nonlinear optics. Additional characterization techniques used in this research include cathodoluminescence, utilizing electron beam excitation in an ultrahigh vacuum chamber, photo-luminescence at cryogenic temperatures, coherent transient spectroscopy, and four-wave mixing. Consequently graduate students receive broad-based training in these table-top methodologies of precision optical science.
Quantum Theory of Coherent Transverse Optical Magnetism, (S. C. Rand), J.O.S.A. B 26, B120 (2009).
Dependence of optically-induced magnetism on molecular electronic structure, (W. M. Fisher and S. C. Rand, J. Lumin), 129, 1407 (2009).
Optically-Induced Magnetization in Homogeneous Dielectric Media, (S. C. Rand, W. M. Fisher, and S. L. Oliveira, J.O.S.A. B 25, 1106 (2008).
Transparent, Polycrystalline Upconverting Nanoceramics: Towards 3-D Displays, (T. R. Hinklin, S. C. Rand, and R. M. Laine), Adv. Mater. 20, 1-4 (2008).
Intense Nonlinear Magnetic Dipole Radiation at Optical Frequencies: Molecular Scattering in a Dielectric Liquid, (Samuel L. Oliveira and Stephen C. Rand), Physical Review Letters 98, 093901 (2007).
Continuous-Wave Amplification and Light Storage in Optically- and Electrically-Pumped Random Media, (B. Li and S. C. Rand), J.O.S.A. B. 24, 799 (2007).
Ultraviolet Emission and Fano Resonance in Doped Nano-Alumina, (B. Li, S. L. Oliveira, T. Hinklin, J. Marchal, J. Azurdia, R. M. Laine and S. C. Rand), J. Appl. Phys. 101, 053534 (2007).
Entropy and Efficiency in Laser Cooling of Solids, (X. Ruan, S. C. Rand and M. Kaviany), Phys. Rev. B 75, 214304 (2007).