1. Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433, USA
2. Department of Physics, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, USA
3. Departments of Physics, Electrical & Computer Engineering, and Mechanical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, USA
4. Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA