[1] Rice Univ, Dept Elect & Comp Engn, Houston, TX 77005 USA
[2] Rice Univ, Lab Nanophoton, Houston, TX 77005 USA
[3] Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA
[4] Lawrence Livermore Natl Lab, Phys & Adv Technol Directorate, Livermore, CA 94550 USA
[5] Univ Calif Davis, NSF, Ctr Biophoton Sci & Technol, Sacramento, CA 95817 USA
[6] Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA