[1] Univ Tennessee, Dept Phys & Astron, Min H Kao Dept Elect Engn & Comp Sci, Knoxville, TN 37996 USA
[2] Univ Tennessee, Inst Adv Mat & Mfg, Knoxville, TN 37996 USA
[3] Univ Vermont, Dept Phys, Burlington, VT 05405 USA
[4] Univ Vermont, Mat Sci Program, Burlington, VT 05405 USA
[5] Univ Rochester, Inst Opt, Ctr Coherence & Quantum Opt, Dept Phys & Astron, Rochester, NY 14627 USA
[6] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA