NEO-PGA: Nonvolatile electro-optically programmable gate array

Area of Science:

• Photonics
• Materials Science
• Integrated Circuits

Background:

• Programmable photonic integrated circuits (PPICs) offer reconfigurable systems but face scalability issues due to volatile thermo-optic tuning, causing high power consumption and thermal crosstalk.
• Chalcogenide phase-change materials (PCMs) present a nonvolatile alternative with significant optical contrast, but optical loss and bit precision have limited their application.

Purpose of the Study:

• To demonstrate a low-loss, multibit control of Sb2Se3, a chalcogenide phase-change material.
• To integrate electrically reconfigurable PCM gates into silicon photonic platforms for scalable PPICs.

Main Methods:

• Utilized a closed-loop "program-and-verify" approach for precise control of Sb2Se3.
• Integrated PCM gates into 300-millimeter silicon photonic platforms, creating both circulating and forward Mach-Zehnder interferometer meshes.

Main Results:

• Achieved low-loss, multibit control of Sb2Se3, overcoming previous limitations.
• Demonstrated broadband switching fabrics and high-Q coupled resonators using the circulating mesh.
• Implemented spatial mode sorting capabilities with the forward mesh.

Conclusions:

• Established a scalable, nonvolatile photonic programmable gate array enabled by PCMs.
• Opened new avenues for general-purpose, on-chip programmable photonic systems.