Nonvolatile multi-level adjustable optical switch based on the phase change material.

Area of Science:

• Photonics and Optical Engineering
• Materials Science for Computing
• Integrated Optics

Background:

• All-optical computation offers advantages in speed and energy efficiency over electronic computation.
• Traditional optical switches face limitations in energy consumption for state maintenance and multi-level adjustability.
• These limitations hinder the development of large-scale photonic integrated circuits and optical spiking neural networks.

Purpose of the Study:

• To design and demonstrate a nonvolatile, multi-level adjustable optical switch.
• To leverage subwavelength grating slot-ridge (SWGSR) waveguides on a silicon platform.
• To utilize the phase change material Ge$_{2}$Sb$_{2}$Te$_{5}$ (GST) for optical modulation.

Main Methods:

• Integration of GST with SWGSR waveguides on a silicon photonic platform.
• Modulation of optical switch transmission by altering the phase state of GST.
• Characterization of optical transmittance changes based on GST phase transitions.

Main Results:

• Achieved a significant optical transmittance modulation of approximately 70%.
• Demonstrated a nonvolatile optical switch requiring no static power to maintain its state.
• The designed switch exhibits superior performance compared to previous optical switch technologies.

Conclusions:

• The developed GST-based SWGSR optical switch offers a promising solution for nonvolatile, multi-level optical switching.
• This technology is well-suited for applications in optical switch matrices and reconfigurable optical spiking neural networks.
• The high transmittance modulation and low power requirements pave the way for advanced photonic integrated circuits.