In this talk, we present our recent findings on compound semiconductor-based nonlinear metasurfaces for all-optical signal processing. Nonlinear metasurfaces have revolutionized the field of nonlinear optics by enabling a radically different way to control light-matter interactions at the subwavelength scale. In this approach, nonlinear optical processes can be maximized by carefully choosing the shape, orientation, and arrangement of subwavelength-scale artificial atoms, called meta-atoms. By introducing Kerr nonlinearity from compound semiconductor materials, such as AlGaAs/GaAs, into a high-quality resonant metasurface, power requirement to achieve optical bistability can be greatly reduced. Optical bistability can has been actively studied due to its potential applications for all-optical switching and optical logic gates. In our research, we will utilize intensity-dependent refractive index in a semiconductor metasurface to realize refractive bistability for all-optical signal processing. Different design strategies will be discussed to excite quasi-bound waves with a high-quality factor and a small mode volume.
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