Enhanced poling and infiltration for highly efficient electro-optic polymer-based Mach-Zehnder modulators.

Area of Science:

• Photonics
• Materials Science
• Electrical Engineering

Background:

• Electro-optic modulators are key components in optical communication and signal processing.
• Miniaturization and increased efficiency are critical for next-generation photonic integrated circuits.

Purpose of the Study:

• To fabricate an ultra-narrow slotted waveguide for highly efficient electro-optic polymer modulators.
• To demonstrate reduced VπL values and enhanced modulation efficiency using novel fabrication techniques.

Main Methods:

• Fabrication of a 40-nm slotted waveguide on a hybrid silicon-organic platform.
• Development of air bridge interconnects and TiO2 carrier barrier for improved polymer infiltration and efficiency.
• Characterization of VπL and modulation efficiency.

Main Results:

• Achieved VπL below 1.19 V.mm for balanced Mach-Zehnder modulators.
• Simulations predict VπL values as low as 0.35 V.mm with doping.
• Demonstrated a 22% improvement in index change efficiency (∂n/∂V) with a 5 nm TiO2 layer.
• Reduced peak poling current by a factor of ~3.

Conclusions:

• The ultra-narrow slotted waveguide enables highly efficient electro-optic polymer modulators.
• Novel fabrication processes, including TiO2 surface treatment, overcome key challenges in miniaturized device fabrication.
• This work paves the way for compact, high-performance modulators for advanced photonic applications.