Ultralow reflectance metal surfaces by ultrafast laser texturing

We report the fabrication of textured metal surfaces by ultrafast laser processing and its optical property characterization by measurement of reflection and scattering as a function of angle and wavelength. The ultrafast laser textured metal surface reflection combined with scattering can be reduced to low values of similar to 3% over a broad spectral and angular range. Furthermore, it is shown that surface optical reflection and scattering can be varied by parameters like laser fluence, number of laser pulses, and coating the textured surfaces with suitable absorbers. It is also shown that ultrafast laser textured metal surfaces can have low surface reflection and scattering properties even at high temperatures (<= 500 degrees C) of operation. (C) 2010 Optical Society of America