Ultra-broadband multimode 3dB optical power splitter using an adiabatic coupler and a Y-branch

Area of Science:

• Photonics
• Integrated Optics
• Optical Communications

Background:

• Mode division multiplexing (MDM) systems require efficient multimode power splitters.
• Existing multimode 3dB power splitters often struggle with low loss, high power balance, and low mode crosstalk.

Purpose of the Study:

• To propose and design an ultra-broadband on-chip multimode 3dB optical power splitter.
• To achieve low insertion loss, high power balance, and low mode crosstalk for MDM systems.

Main Methods:

• Utilizing an adiabatic coupler and an S-bend based Y-branch for the power splitter design.
• Designing a splitter for the four lowest modes on a silicon on insulator (SOI) platform.
• Conducting simulations to evaluate device performance.

Main Results:

• Achieved insertion losses below 0.12dB.
• Maintained power imbalances within ± 0.38dB.
• Demonstrated mode crosstalks below -18.5dB for the four lowest modes.
• Operated across an ultra-broadband wavelength range of 165 nm (1400 nm to 1565 nm).

Conclusions:

• The proposed on-chip multimode 3dB optical power splitter meets key performance metrics for MDM systems.
• The design offers excellent performance over a wide wavelength range, suitable for practical applications.
• Fabrication tolerance analysis of the adiabatic coupler was also performed.