Surface ablation of RbTiOPO4 by femtosecond laser

We report here the results obtained in surface ablation of RbTiOPO4 single crystals by femtosecond laser. We fabricated and characterized one-dimensional (1D) diffraction gratings with different lattice spacings of 15 and 20 μm, and with a sub-modulation of the period introduced in the later. The optical and electronic microscopy characterization and filling factor analysis of these diffraction gratings are reported. We also show that the roughness generated on the grooves by the ablation process can be improved by chemical etching.

► Fabrication of diffraction gratings on RbTiOPO4 crystals by ultrafast laser ablation. ► Same quality than that on other non-linear optical materials by the same technique. ► Lattice parameters and filling factors determined by optical methods. ► Potential applications in non-collinear phase matching and signal multiplexing.