Random lasing emission and oscillation in femtosecond laser machined microstructured Nd3+-doped (Pb, La)(Zr, Ti)O3 (10/65/35) ceramics

Cylindrical shaped microstructured surface of Nd3+-doped lanthanum lead zirconate titanate ceramics with an average size of around 230 nm in diameter were machined by femtosecond laser irradiation in SF6 atmosphere to increase the scattering strength on the surface. Multi-mode random lasing emission and lasing oscillation centered at 876 nm were investigated using a 532 nm nanosecond laser in the laser-machined region of the specimen. Both the scatterers provided by the laser-machined microstructure and the recurrent photoinduced trapping and re-excitation process participated in the weak localization of light and enhancement of lasing emission. Short-lived scatterers and relaxation oscillation behavior were measured experimentally, which proved the validity of the physical picture. This work offers new insight to modify the luminescence property of laser materials, and enlarge the range of exploration of weak localization of light and random lasers.