Real-Time Programmable Nonlinear Wavefront Shaping with Si Metasurface Driven by Genetic Algorithm

Area of Science:

• Optics and Photonics
• Metamaterials
• Nonlinear Optics

Background:

• Nonlinear wavefront shaping is vital for optical computation, information processing, and imaging.
• Current methods using metasurfaces offer limited flexibility as wavefronts are fixed after fabrication, requiring multiple devices.

Purpose of the Study:

• To develop a dynamic and flexible method for nonlinear wavefront shaping using a single metasurface.
• To reduce the inefficiency and time constraints associated with fabricating multiple metasurfaces for different wavefronts.

Main Methods:

• Combined evolutionary algorithms, specifically a genetic algorithm (GA), with spatial light modulators (SLMs).
• Utilized a silicon (Si) metasurface for third-harmonic generation (THG) of visible light from near-infrared light.
• Leveraged multipolar Mie resonances in the Si metasurface to enhance light-matter interactions and THG emission.

Main Results:

• Demonstrated dynamic control of nonlinear wavefronts using a single metasurface.
• Achieved arbitrary nonlinear wavefront pattern generation with reduced alignment complexity.
• The cubic relationship in THG emission minimized noise in SLM-produced diffractive patterns, enabling precise engineering.

Conclusions:

• The developed approach enables self-optimized nonlinear wavefront shaping.
• This method significantly advances optical computation and information processing by offering a flexible and efficient solution.
• Paves the way for dynamic control of light at the nanoscale.