Waveguide self-coupling based reconfigurable resonance structure for optical filtering and delay.

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Waveguide Devices

Background:

• Conventional microring resonators face limitations in compactness and fabrication tolerance.
• Achieving high-order resonance and tunable responses often requires complex designs.

Purpose of the Study:

• To introduce a novel waveguide self-coupling resonator.
• To demonstrate its capability as a flat-top tunable filter and tunable delay line with low group delay dispersion.

Main Methods:

• Theoretical analysis using the transfer-matrix method.
• Investigating mutual mode coupling between clockwise and counter-clockwise resonance eigenmodes.
• Deriving relations for phase shifters to achieve desired optical responses.

Main Results:

• The proposed structure exhibits high-order resonance features due to coupled eigenmodes.
• It functions as a second-order tunable filter and a tunable delay line with low group delay dispersion.
• The device is inherently more compact and resilient to fabrication errors.

Conclusions:

• The novel waveguide self-coupling resonator offers a simpler and more power-efficient approach to device reconfiguration.
• It presents a promising alternative to conventional microring resonators for integrated photonic applications.