Compact Q-switched vortex waveguide laser modulated by buried Ag nanoparticles in SiO2.

• A high-performance Q-switched vortex laser has been realized on a waveguide platform. • The pulse width (28 ns) is the shortest ever reported for Q-switched vortex laser. • The near-field distributions of nanoparticles arrays have been simulated. Vortex beam, particularly pulsed vortex laser, has expanded the potential applications in optics due to their unique wave-front phase structure and the determined photon orbital angular momentum. In this study, we present a novel approach including the integration of fused silica embedded with silver nanoparticles (Ag:SiO 2) into the Nd:YAG waveguide platform for achieving nanosecond vortex pulses. Using a spiral phase plate for in-cavity phase modulation, we successfully demonstrate a Q-switched vortex laser with a high repetition rate in the megahertz range and short pulse width in the nanosecond regime. Additionally, we conduct a comprehensive analysis of the near-field distributions of Ag nanoparticles with varying sizes and distributions using COMSOL simulation. This study exemplifies the integration of silica-based photonic elements for realizing a high-stability and cost-effective nanosecond vortex laser system. [ABSTRACT FROM AUTHOR]