Inverse design of efficient waveguide crossing with phase correction

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Materials Science

Background:

• Waveguide crossings are essential components in integrated photonic circuits.
• Achieving simultaneous optimization of transmission efficiency and phase response in crossings remains a challenge.
• Minimizing insertion loss and phase error is critical for device performance.

Purpose of the Study:

• To design, fabricate, and characterize a novel waveguide crossing with integrated phase-correction functionality.
• To optimize the device for simultaneous high transmission efficiency and accurate phase response.
• To demonstrate the performance of the device on a silicon-on-insulator platform.

Main Methods:

• Design and fabrication of a waveguide crossing using silicon-on-insulator (SOI) technology.
• Development of an objective function incorporating insertion loss (IL) and phase error for simultaneous optimization.
• Experimental characterization of the device's optical performance, including IL and phase error.
• Focus on the TE0 mode for optical signal transmission.

Main Results:

• The waveguide crossing was successfully fabricated with an 8 × 8 µm² footprint.
• Experimental results demonstrate an average insertion loss below 0.11 dB across a 1535-1565 nm wavelength range.
• A low phase error of 1.86° was achieved for the TE0 mode.
• Simultaneous optimization of transmission efficiency and phase response was validated.

Conclusions:

• The developed waveguide crossing effectively corrects phase errors while maintaining high transmission efficiency.
• The SOI platform enables the creation of compact and high-performance integrated photonic devices.
• This technology holds promise for advancing optical communication and signal processing systems.