Fabrication and characterization of optimized corner-cut square microresonators

Area of Science:

• Photonics and Optical Engineering
• Micro- and Nanophotonics
• Integrated Optics

Background:

• Waveguide-coupled microresonators are essential components in integrated photonic circuits.
• Modifying resonator geometry can tune optical properties and enhance performance.
• Silicon-on-insulator (SOI) platforms offer excellent optical properties for microresonator fabrication.

Purpose of the Study:

• To design, fabricate, and characterize novel corner-cut square microresonators.
• To optimize resonator geometry and coupling parameters using electromagnetic simulations.
• To validate simulation results with experimental measurements.

Main Methods:

• Rigorous Finite-Difference Time-Domain (FDTD) analysis for electromagnetic simulations.
• Optimization of corner-cut length, coupling gap, and waveguide width.
• Fabrication using electron-beam lithography and dry etching on SOI substrates.
• Experimental characterization of fabricated microresonators.

Main Results:

• Identification of an optimal corner-cut length for enhanced resonator performance.
• Demonstration of optimized coupling gap and waveguide width through simulation.
• Successful fabrication of corner-cut square microresonators on SOI.
• Experimental results show excellent agreement with FDTD simulations.

Conclusions:

• Corner-cut square resonators offer improved performance compared to standard square resonators.
• Rigorous FDTD analysis is a reliable tool for optimizing microresonator design.
• The developed fabrication process is suitable for producing high-performance integrated photonic devices.