All-optic control using a photo-thermal heater in Si photonics

Area of Science:

• Photonics
• Materials Science
• Optical Engineering

Background:

• Silicon photonics enables integrated optical circuits.
• All-optic control methods are sought for efficient device operation.
• Photo-thermal effects offer a pathway for non-electrical control.

Purpose of the Study:

• To demonstrate a simple all-optic control for silicon photonics.
• To utilize photo-thermal heating for phase tuning of signal light.
• To compare the efficiency of all-optic control with electrical heating.

Main Methods:

• Designed and fabricated Mach-Zehnder and microring devices.
• Utilized a heavily doped waveguide for control light absorption.
• Employed thermal diffusion for phase tuning in an adjacent signal waveguide.
• Measured control power requirements and heating efficiency.

Main Results:

• Achieved all-optic control with low power consumption (17 mW for π-phase shift, 4 mW for 6 dB extinction).
• Demonstrated efficient phase tuning via thermal diffusion.
• Confirmed superior heating efficiency compared to electrical heaters.

Conclusions:

• The proposed all-optic photo-thermal heater is a viable and efficient control method for silicon photonics.
• This approach offers a promising alternative to electrical control for integrated photonic devices.
• The demonstrated devices show potential for various silicon photonic applications requiring optical modulation.