Integrated photonic power divider with arbitrary power ratios

Area of Science:

• Photonics
• Nanotechnology
• Integrated Optics

Background:

• Integrated optical power splitters are essential for photonic integrated circuits.
• Conventional devices struggle with arbitrary split ratios, especially for multiple outputs.
• Existing technologies present limitations in miniaturization and precise power division.

Purpose of the Study:

• To design and demonstrate an ultra-compact optical power splitter.
• To achieve arbitrary and precise light power splitting ratios.
• To overcome limitations of conventional power splitters in photonic integrated circuits.

Main Methods:

• Utilized a nonlinear fast search method for nanostructure design.
• Employed a QR code-like arrangement of dielectric or air square pixels (120x120 nm).
• Engineered light scattering and superposition from optimized etched square locations.

Main Results:

• Demonstrated 1x2 splitters with 1:1, 1:2, and 1:3 ratios, and a 1x3 splitter with a 1:2:1 ratio.
• Achieved an ultra-compact footprint of only 3.6x3.6 µm for all devices.
• Measured transmission efficiencies close to 80% over a 30 nm wavelength range with well-controlled split ratios.

Conclusions:

• The QR code-like nanostructure enables ultra-compact and highly functional optical power splitters.
• This design overcomes challenges in achieving arbitrary split ratios for multi-output devices.
• The developed power splitters offer a promising solution for advanced photonic integrated circuits.