1. Wellman Center for Photomedicine; Harvard Medical School and Massachusetts General Hospital; Boston MA 02114 USA
2. Department of Electrical Engineering; Indian Institute of Technology Bombay; Mumbai 400076 India
3. Department of Electrical Engineering; University of California Los Angeles; CA 90095 USA
4. Califronia NanoSystems Institute; University of California Los Angeles; CA 90095 USA
5. Department of Bioengineering; University of California Los Angeles; CA 90095 USA
6. Department of Surgery, David Geffen School of Medicine; University of California Los Angeles; CA 90095 USA