Multiport Programmable Silicon Photonics Using Low-Loss Phase Change Material Sb₂Se₃.

Area of Science:

• Photonics and Optical Engineering
• Materials Science for Photonic Applications
• Integrated Optics and Silicon Photonics

Background:

• Scalable and efficient reconfigurable photonic processors are essential for next-generation technologies.
• Optical phase-change materials (PCMs) offer potential for compact and efficient optical devices.
• Antimony selenide (Sb₂Se₃) is a promising PCM due to its ultra-low-loss properties.

Purpose of the Study:

• To present an experimental platform for reconfigurable multiport devices using Sb₂Se₃ on silicon photonics.
• To demonstrate the encoding of multiport operations onto the transmission matrix of a multimode interferometer.
• To explore the scalability and performance of Sb₂Se₃-based reconfigurable optical devices.

Main Methods:

• Fabrication of multiport devices using a standard 220 nm silicon photonics platform.
• Cladding the devices with a thin film of Sb₂Se₃.
• Utilizing direct laser writing to induce local refractive index perturbations for device programming.

Main Results:

• Demonstrated a range of multiport geometries, from 2x2 up to 5x5 couplers.
• Achieved simultaneous control of up to 25 matrix elements with 90% programming accuracy.
• Observed consistent optical performance across the C-band spectrum.

Conclusions:

• The developed platform enables compact and efficient reconfigurable multiport devices.
• This approach offers a pathway to large-scale reconfigurable photonic processors with significantly reduced footprints.
• Sb₂Se₃ is a viable material for high-performance, reconfigurable integrated photonic devices.