Broadband unidirectional visible imaging using wafer-scale nano-fabrication of multi-layer diffractive optical...

Area of Science:

• Optics and Photonics
• Artificial Intelligence
• Nanotechnology

Background:

• Unidirectional imaging is crucial for advanced optical systems, but existing methods often lack broadband operation or polarization insensitivity.
• Diffractive optical elements offer miniaturization and multi-functionality but require sophisticated design and fabrication.

Purpose of the Study:

• To develop a broadband and polarization-insensitive unidirectional imager operating in the visible spectrum.
• To demonstrate wafer-scale fabrication of AI-designed diffractive optical processors for unidirectional imaging.

Main Methods:

• Utilized deep learning for diffractive optical design.
• Employed wafer-scale nano-fabrication with high-purity fused silica.
• Incorporated 16 levels of nanoscale phase features across two diffractive layers.

Main Results:

• Achieved unidirectional imaging across red, green, and blue visible wavelengths.
• Experimentally validated high-fidelity forward imaging and blocked backward propagation.
• Demonstrated wafer-scale production of diffractive processors with ~0.5 billion features per wafer.

Conclusions:

• Established a pathway for AI-enabled diffractive optics with versatile applications.
• Signaled a new era in optical device functionality with industrial-scale, massively scalable fabrication.
• Paved the way for mass production of multi-layer diffractive processors for large apertures and parallel processing.