In this study we propose a unique method to increase the weblike silicon nanofibrous structures formation using dual wavelength double pulse femtosecond laser radiation under ambient condition. The augmentation of nanostructures is evidenced from the difference in nanofibrous structure layer thickness. Enhancement in generation is explained through the increase in excited state electrons with double pulse as compared to single pulse. Moreover the absorption characteristic of irradiated surface undergoes significant changes after the first pulse (515 nm) which enhances absorption for the second pulse (1030 nm) and consequently results in an increase in nanostructures.
Dr. Sivakumar M., Tan, B., and Venkatakrishnan, K., “Enhancement of Silicon Nanostructures Generation Using Dual Wavelength Double Pulse Femtosecond Laser Under Ambient Condition”, Journal of Applied Physics, vol. 107, p. 044307, 2010.