Segmented waveguide arrays: deriving discrete diffraction relations in a square lattice photonic crystal.

Area of Science:

• Photonics
• Optical Engineering
• Materials Science

Background:

• Segmented waveguide arrays are key components in photonic integrated circuits.
• Controlling light propagation in these structures is crucial for device functionality.
• Photonic crystals offer unique platforms for manipulating light.

Purpose of the Study:

• To investigate segmented strip-loaded waveguide arrays within a square lattice photonic crystal.
• To develop a rigorous discrete diffraction approach for analyzing light propagation.
• To establish an effective waveguide array model and validate it experimentally.

Main Methods:

• Derivation of a full multiband discrete diffraction approach.
• Analysis of near-axial injection along a lattice vector.
• Development of a simplified single-band scheme.
• Validation through beam deviation experiments.

Main Results:

• An effective waveguide array picture was obtained.
• A quasi-linear dependence on the segmentation ratio was identified in the single-band scheme.
• Experimental validation confirmed the theoretical model's accuracy.

Conclusions:

• The derived diffraction framework allows for efficient phase map shaping in waveguide arrays.
• This work expands the engineering capabilities for photonic crystals.
• Introduces in-plane free propagation structures for discrete photonics.