Thin heterogeneous SOI waveguides for thermo-optical tuning and filtering

Area of Science:

• Photonics and Optical Engineering
• Semiconductor Devices
• Integrated Optics

Background:

• Reconfigurable Optical Add/Drop Multiplexers (ROADMs) are crucial for flexible optical networks.
• Existing ROADM technologies face challenges in miniaturization, efficiency, and tunability.
• Silicon-on-insulator (SOI) platforms offer potential for integrated photonic devices.

Purpose of the Study:

• To analyze and simulate novel heterogeneous SOI waveguide structures for ROADM applications.
• To investigate the integration of thermo-optic tuning and multi-reflector beam expanders.
• To achieve quasi mono-mode behavior and efficient fiber coupling.

Main Methods:

• Design of heterogeneous SOI ridge waveguides with specific silicon core dimensions (220 nm x 16 µm).
• Incorporation of p(+) side-doping for mode-dependent optical losses.
• Utilizing nano-structured 2D-gratings for fiber coupling and polarization diversity.
• Employing nano-grooves or p(+) doping reflector strips for beam expanders.
• Implementing local heaters for wideband thermo-optic tuning.

Main Results:

• Demonstrated quasi mono-mode behavior in SOI waveguides through controlled optical losses.
• Simulated efficient fiber coupling and polarization diversity using nano-structured gratings.
• Validated the effectiveness of p(+) doping reflector strips and nano-grooves for beam expansion.
• Showcased wideband thermo-optic tuning capabilities via integrated heaters.

Conclusions:

• The proposed heterogeneous SOI waveguide structures are promising for advanced ROADM devices.
• The design enables enhanced performance characteristics such as mode control and efficient coupling.
• This work contributes to the development of more compact and versatile optical networking solutions.