1. Department of Physics, University of Arizona, Tucson, Arizona 85721, United States
2. Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
3. Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
4. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
5. Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, United States
6. James C. Wyant College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, United States