Sb₂Se₃-assisted reconfigurable broadband Y-junction

Area of Science:

• Photonics and Optical Engineering
• Materials Science
• Integrated Optics

Background:

• Y-junctions are crucial broadband components in on-chip systems.
• Traditional Y-junctions lack tunability, limiting their application as passive elements.
• Reconfigurable optical components are essential for advanced communication networks.

Purpose of the Study:

• To develop a reconfigurable broadband Y-junction using phase change material (Sb₂Se₃).
• To enable dual-mode operation as a (de)multiplexer and a 3-dB power splitter.
• To achieve quasi-adiabatic evolution for efficient switching in a compact device.

Main Methods:

• Integration of Sb₂Se₃ layers into a Y-junction structure.
• Utilizing different states (amorphous/crystalline) of Sb₂Se₃ for distinct optical functions.
• Employing a segmented fast quasi-adiabatic method for optimized device performance.
• Simulating device performance, including bandwidth, crosstalk, and insertion loss.

Main Results:

• The Y-junction demonstrates reconfigurable dual-mode operation: (de)multiplexer and 3-dB power splitter.
• Achieved bandwidth exceeding 100 nm with crosstalk below -20 dB.
• Compact device footprint of 19.3 × 3 µm².
• Simulated crosstalk < -41 dB and insertion loss < 0.12 dB for the (de)multiplexer state.
• Excess loss within 0.06 dB for the power splitter state.

Conclusions:

• The proposed phase-change-material-based Y-junction offers reconfigurable functionality for optical networks.
• The device provides high performance (bandwidth, low loss, low crosstalk) in a small footprint.
• This technology can advance the development of flexible and high-bandwidth mode-division-multiplexing systems.