Polymer/Silica Hybrid Waveguide Thermo-Optic VOA Covering O-Band

Area of Science:

• Photonics and Optical Engineering
• Materials Science
• Integrated Optics

Background:

• Variable optical attenuators (VOAs) are crucial components in optical communication systems for managing signal power.
• Existing VOA technologies face challenges in terms of cost, performance, and integration.
• Thermo-optic devices offer a promising avenue for VOA development due to their potential for low loss and high extinction ratios.

Purpose of the Study:

• To demonstrate a novel polymer/silica hybrid waveguide thermo-optic variable optical attenuator (VOA) operating in the O-band.
• To investigate the performance characteristics of the fabricated VOA, including extinction ratio, attenuation, and switching speed.
• To showcase the feasibility of using direct ultraviolet (UV) lithography for cost-effective VOA fabrication.

Main Methods:

• Fabrication of a polymer/silica hybrid waveguide structure using direct ultraviolet (UV) lithography.
• Optimization of multimode interference (MMI) couplers within a Mach-Zehnder interferometer (MZI) configuration for low loss and wide bandwidth.
• Characterization of the VOA's optical and electro-optic performance, including extinction ratio, attenuation, power consumption, and switching times.

Main Results:

• The demonstrated VOA operates effectively in the O-band.
• An extinction ratio (ER) of 18.64 dB at 1310 nm was achieved with a low power consumption of 8.72 mW.
• The device exhibits an attenuation greater than 6.99 dB across the O-band, with rapid rise and fall times of 184 μs and 180 μs, respectively.

Conclusions:

• A cost-effective polymer/silica hybrid waveguide thermo-optic VOA has been successfully demonstrated using direct UV lithography.
• The optimized MMI-based MZI design enables low loss and wide bandwidth operation.
• The achieved performance metrics indicate the suitability of this VOA for O-band optical communication applications.