Dielectric‐Metasurface‐Enhanced Kerr Self‐Modulation for Passively Q‐Switching

Abstract

AbstractDielectric metasurfaces are highly sought‐after since they have found a variety of linear and nonlinear applications. Here, a novel transmission modulation is presented for pulsed laser generation by directly exploiting the enhanced Kerr effect from a periodic array of silicon nanodisks. The Mie resonance of the unit cells enhances the Kerr effect of the silicon material and is redshifted by the latter, so that the transmission of the metasurface at the working wavelength is strongly modulated (the observed modulation depth is above 3% under moderate exciting power). By inserting the fabricated metasurface as a self‐modulator into a ring cavity fiber laser, stable Q‐switched pulse laser output is achieved with a duration of 1.4 µs and a repetition rate of 60 kHz. This work opens a door for ultra‐thin low‐loss dielectric metasurfaces to efficiently shape the operation of pulsed lasing based on their enhanced nonlinear effects and flexible propagation manipulation.