Multi-photon fabrication of two-dimensional periodic structure by three interfered femtosecond laser pulses on the surface of the silica glass

Two-dimensional periodic structures have been fabricated on the surface of the silica glass by multi-photon absorption using three noncoplanar interfered femtosecond laser pulses. The fabricated structure with hexagonal lattice can be observed from the microscopy. The three-dimensional structure of the periodic pattern is revealed by an atomic force microscopy (AFM). Diffraction pattern of the microstructure has been observed with a laser beam at wavelength of 400 nm. The experimental results show that the fabricated microstructure can be utilized as a multi-beam-splitter.