Fabrication-constrained nanophotonic inverse design

Area of Science:

• Nanophotonics
• Computational Design
• Integrated Optics

Background:

• Computational design methods for nanophotonic devices often neglect fabrication constraints, limiting practical application.
• Ensuring the manufacturability of complex nanophotonic structures is a significant challenge in the field.

Purpose of the Study:

• To introduce a general inverse design algorithm for nanophotonic devices that directly incorporates fabrication constraints.
• To demonstrate the algorithm's capability in designing various nanophotonic devices, including a power splitter.

Main Methods:

• Developed a general inverse design algorithm for nanophotonic devices.
• Integrated fabrication constraints directly into the computational design process.
• Designed and experimentally validated a compact, broadband 1x3 power splitter on a silicon photonics platform.

Main Results:

• Successfully designed a spatial-mode demultiplexer, wavelength demultiplexer, and directional coupler.
• Demonstrated a compact (3.8x2.5 μm) broadband 1x3 power splitter on silicon photonics.
• The fabricated splitter met typical silicon photonics design rules (100 nm minimum radius of curvature).
• Measured insertion loss was 0.642 ± 0.057 dB and power uniformity was 0.641 ± 0.054 dB over 1400-1700 nm.

Conclusions:

• The developed inverse design algorithm effectively incorporates fabrication constraints for nanophotonic devices.
• The demonstrated power splitter showcases the practical utility of the algorithm for creating efficient and compact photonic integrated circuits.
• This method advances the design and fabrication of complex nanophotonic devices for various applications.