1. Department of Electrical and Computer Engineering, University of Delaware, Newark, DE 19716, USA.
2. II-VI Incorporated, 48800 Milmont Drive, Milmont, CA 94538, USA.
3. NASA Goddard Space Flight Center, Lasers and Electro-Optics Branch, Greenbelt, MD 20771, USA.
4. Department of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA.