Proposal for ideal 3-dB splitters-combiners in photonic crystals

Area of Science:

• Photonics
• Optical Engineering
• Materials Science

Background:

• Ideal 3-dB splitters are achievable in three-port photonic crystal systems.
• Ideal 3-dB combiners are not feasible in three-port photonic crystal systems due to strong photon confinement and lack of loss paths.

Purpose of the Study:

• To propose a novel structure for ideal 3-dB splitter-combiners in photonic crystals.
• To overcome the limitations of three-port systems for combiner functionality.

Main Methods:

• Adoption of a four-port system inspired by microwave circuit rat-race circuits.
• Investigation of design conditions for two-dimensional photonic-crystal-based rat-race circuits using coupled-mode theory in time.
• Numerical performance calculation using the finite-difference time-domain (FDTD) method.

Main Results:

• A functional 3-dB splitter-combiner structure based on the rat-race circuit concept was designed.
• The proposed four-port system enables ideal 3-dB combining, unlike previous three-port approaches.

Conclusions:

• The proposed four-port rat-race circuit structure is a viable solution for achieving ideal 3-dB splitter-combiners in photonic crystals.
• This design advances the development of efficient optical signal manipulation components.