Polarization controlled deep sub-wavelength periodic features written by femtosecond laser on nanodiamond thin film surface.

Deep sub-wavelength (Δ/λ= ~0.22) periodic features are induced uniformly on a nanodiamond (ND) thin film surface using femtosecond (fs) laser irradiation (pulse duration = ~110 fs and central wavelength of 800 nm). The topography of the surface features is controlled by the laser polarization. Orientation of features is perpendicular to laser polarization. Periodicity (spatial periodicity of<λ/4) of the surface features is less than the laser wavelength. This work gives an experimental proof of polarization controlled surface plasmon-fs laser coupling mechanism prompting the interaction between fs laser and solid matter (here ND thin film) which in turn is resulting in the periodic surface features. Scanning electron microscopy in conjunction with micro Raman scattering, X-ray diffraction, and atomic force microscopy are carried out to extract surface morphology and phase information of the laser irradiated regions. This work demonstrates an easy and efficient surface fabrication technique. [ABSTRACT FROM AUTHOR]