Self-assembly of tunable and highly uniform tungsten nanogratings induced by a femtosecond laser with nanojoule energy

The authors are indebted to Dr Andrey Kapitonov for many enlightening discussions. This project is financially supported in part by NSF through grant CMMI-0708555 and by DARPA through grant no. W911NF-05-2-0053. HZ is grateful for the financial support from the Center for Optoelectronics and Optical Communications (DARPA grant no. W911NF- 04-1-0319), Mechanical Engineering and Engineer Science Department, Department of Chemistry, and Provost of UNC at Charlotte.