1. Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249, USA.
2. Department of Physics, Wesleyan University, Middletown, CT 06457, USA.
3. Air Force Research Laboratory, Directed Energy Directorate, Kirtland AFB, NM 87117, USA.
4. Air Force Research Laboratory, Sensors Directorate, Wright-Patterson AFB, OH 45433, USA.