National Research Council, Steacie Institute for Molecular Sciences, Chalk River, Ontario K0J 1J0, Canada, Raman Research Institute, Bangalore 560 080, India, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1, Canada, York Department of Chemical Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, and Department of Physics, St. Francis Xavier University, Antigonish, Nova Scotia B2G 2W5,... (At 2005-06-17)