Optical Waveguide Tunable Phase Delay Lines Based on the Superior Thermo-Optic Effect of Polymer

Area of Science:

• Optoelectronics
• Materials Science
• Photonics

Background:

• Polymers exhibit a strong thermo-optic effect, beneficial for tunable phase-delay devices requiring low power and wide tuning ranges.
• Increasing temperature for wider tuning ranges can cause light attenuation and refractive index gradients in waveguide cores.

Purpose of the Study:

• To identify the optimal waveguide structure for variable phase delay lines.
• To investigate attenuation and interference phenomena during phase modulation in different polymer waveguide structures.

Main Methods:

• Evaluated three distinct waveguide structures.
• Analyzed attenuation and interference patterns associated with phase modulation.
• Focused on improving thermal distribution uniformity within the waveguide core.

Main Results:

• Identified an optimal waveguide structure for variable phase delay applications.
• Achieved a significant phase delay of 130π radians.
• Maintained low output light attenuation, below 0.5 dB.

Conclusions:

• Optimized polymer waveguide design can overcome limitations of thermo-optic devices.
• Uniform thermal distribution is key to achieving high phase delay with low loss.
• The findings enable efficient, low-power tunable optical phase modulation.