Erasable and rewritable laser-induced gratings on silver phosphate glass

Abstract

We herein report on the fabrication of high regularity, erasable and rewritable periodic surface patterns on silver metaphosphate glass (AgPO3) by means of ultrashort pulsed laser processing. The laser-induced periodic surface structures (LIPSS) are formed perpendicular to the laser beam polarization, exhibiting a periodicity similar to the laser wavelength. Notably, the so-formed periodic patterns can be readily erased upon further exposure to femtosecond laser irradiation under controlled conditions. This all-laser inscription and deletion protocol allows the reversible patterning of the phosphate glass surface by employing a single laser beam. Optical and Raman spectroscopy revealed that the formation of the periodic patterns and the erasing process do not cause any phosphate network modifications or structural damage on the glass, and thus, proving that the demonstrated reversible LIPSS process is entirely non-ablative. This remarkable feature could enable infinite cycles of the write/erase/re-write process on the same area of the glassy material, posing the AgPO3 glass as an important candidate for waveguides and optical responsive memory components of advanced photonic applications.