Near-Infrared All-Optical Switching Based on Nano/Micro Optical Structures in YVO4 Matrix: Embedded Plasmonic Nanoparticles and Laser-Written Waveguides

Nonlinear interactions between light and matter give rise to a wide range of applications for both fundamental and applied research. Herein, near-infrared switching of the optical response based on embedded Ag nanoparticles and laser-written optical waveguides within yttrium vanadate (YVO4) crystal matrix is demonstrated. Using broadband transient absorption spectroscopy with a combination of femtosecond Z-scan spectroscopy, the plasmon-enhanced features of the third-order optical nonlinearity in Ag:YVO4 nanocomposite at the near-infrared band are elucidated. Meanwhile, an optical-lattice-like microscale waveguide is fabricated with well-preserved photoluminescence properties by femtosecond laser writing. Taking advantage of the ultrafast on-off switching behavior of Ag:YVO4 saturable absorber, a Q-switched pulsed laser operation in the waveguide platform, delivering 1 mu m light pulses with high peak power of 298 mW, is demonstrated. This work indicates a possible path for the development of chip-scale ultrafast photonic devices.