Compact resonant 2 × 2 crossbar switch using three coupled waveguides with a central nanobeam

Area of Science:

• Photonics and Optical Engineering
• Materials Science
• Nanotechnology

Background:

• Optical switching is crucial for modern communication networks.
• Existing solutions face limitations in size, power consumption, and integration.

Purpose of the Study:

• To theoretically design and simulate novel 2x2 optical crossbar switches using silicon-on-insulator (SOI) and germanium-on-nitride platforms.
• To evaluate their performance metrics for potential use in wavelength-division-multiplexed cross-connect (WXC) systems.

Main Methods:

• Utilized a three-waveguide coupler with a thermo-optical (TO) actuated nanobeam.
• Employed the 3D finite difference time domain (FDTD) approach for accurate design and simulation.
• Evaluated insertion loss (IL) and crosstalk (CT) by varying structural parameters and TO-induced index changes.

Main Results:

• Achieved excellent predicted insertion loss (IL) and crosstalk (CT) performance.
• Demonstrated the feasibility of compact, nonblocking space-and-wavelength routing switches.
• Projected designs suitable for monolithic, industry-standard SOI and Ge-on-nitride chip integration.

Conclusions:

• The designed optical crossbar switches are fundamental building blocks for wavelength-division-multiplexed cross-connect (WXC) applications.
• The proposed devices offer compact, reconfigurable, and high-performance routing capabilities.
• These switches pave the way for advanced WXC architectures, including programmable hexagonal and diamond meshes.