1Materials Department, University of California Santa Barbara, Building 503, Santa Barbara, CA 93106–5050 USA
2Materials Science Engineering Department, University of Michigan, 3062D HH. Dow Building–2300 Hayward Street Ann Arbor, MI 48109 USA
3Department of Applied Physics, 2477 Randall Laboratory–450 Church St. Ann Arbor, MI 48109, USA
4Center for Ultrafast Optical Science, 1012 Gerstacker Bldg. 2200 Bonisteel Blvd, Ann Arbor, MI 48109, USA
5Materials Department, Building 503, Room 1355, Santa Barbara, CA 93106–5050 USA