On-chip nonvolatile and erasable silicon waveguide filter based on a low-loss phase-change material

Area of Science:

• Photonics and Materials Science
• Integrated Optics
• Phase-Change Materials

Background:

• Silicon waveguide filters are crucial for optical signal processing but their function is fixed post-fabrication.
• Existing tuning methods (electro-optical, thermo-optical) offer limited spectral modification.
• The need for reconfigurable and nonvolatile optical filters is critical for advanced photonic applications.

Purpose of the Study:

• To propose and demonstrate a novel nonvolatile and erasable silicon waveguide filter.
• To utilize the phase-change properties of Sb2Se3 for dynamic grating formation.
• To enable real-time modification of optical filter characteristics on-chip.

Main Methods:

• Fabrication of a silicon waveguide with an integrated Sb2Se3 layer.
• Utilizing laser irradiation to induce phase transitions in Sb2Se3 for grating inscription/erasure.
• Characterization of the filter's optical transmission states and tunability.

Main Results:

• Demonstrated a nonvolatile and erasable silicon waveguide filter.
• Achieved real-time writing and erasing of arbitrary grating structures using laser irradiation.
• Observed three distinct working states: low-loss transmission, Bragg reflection, and Fabry-Pérot resonance.
• Showcased online modification of grating parameters (period, width, duty cycle, number, phase shift).

Conclusions:

• The proposed Sb2Se3-based silicon waveguide filter offers a low-cost, low-power, and erasable solution for reconfigurable optical filtering.
• This technology overcomes limitations of traditional fabrication methods for dynamic filter adjustment.
• The developed erasable processing method holds significant promise for programmable photonic and quantum circuits.