Unprecedented highest electro-optic coefficient of 226 pm/V for electro-optic polymer/TiO₂ multilayer slot waveguide...

Area of Science:

• Materials Science
• Optoelectronics
• Polymer Science

Background:

• Nonlinear optic (NLO) polymers are crucial for electro-optic (EO) devices.
• Developing efficient coating layers is key to enhancing EO polymer performance.
• Titanium dioxide (TiO₂) and sol-gel silica are promising materials for such layers.

Purpose of the Study:

• To investigate the electrical and optical properties of TiO₂ and sol-gel silica as coating layers.
• To evaluate their impact on EO polymer performance in multilayer slot waveguide modulators.
• To optimize poling conditions for enhanced EO coefficients.

Main Methods:

• Fabrication of EO polymer/TiO₂ multilayer slot waveguide devices.
• Ellipsometric reflective technique (Teng and Man) for EO coefficient measurement.
• Optimization of poling for TiO₂ and sol-gel silica cladding.

Main Results:

• The Pockels coefficient was significantly enhanced.
• Achieved coefficients of 226 pm/V at 1.31 μm and 198 pm/V at 1.55 μm.
• Optimal poling with TiO₂ and sol-gel silica cladding yielded the highest enhancements.

Conclusions:

• TiO₂ and sol-gel silica are effective coating layers for EO polymer waveguides.
• The developed multilayer structure demonstrates high potential for NLO applications.
• The study provides a pathway for designing advanced EO modulators.