Narrow frequency and sharp angular defect mode in one-dimensional photonic crystals from a photonic heterostructure

Area of Science:

• Photonics
• Condensed Matter Physics
• Materials Science

Background:

• Defective photonic crystals (PCs) are engineered structures that control light propagation.
• Photonic heterostructures offer unique optical properties by combining different PC structures.
• Achieving narrow frequency and sharp angular selectivity in optical devices is a significant challenge.

Purpose of the Study:

• To design and investigate a novel photonic heterostructure.
• To achieve a defect mode with simultaneous narrow frequency and sharp angular selectivity.
• To explore the potential of this heterostructure for advanced optical filter applications.

Main Methods:

• Combining two one-dimensional defective photonic crystals (PCs) to form a heterostructure.
• Designing the sub-PCs to achieve specific defect mode frequency behaviors at different incident angles.
• Analyzing the frequency and angular characteristics of the resulting defect mode.

Main Results:

• A photonic heterostructure exhibiting a defect mode with narrow frequency and sharp angular selectivity was successfully obtained.
• The key design principle involves matching defect mode frequencies at one incident angle while differentiating them at others.
• Optical filters based on this heterostructure demonstrate a narrow-frequency passband and sharp angular pass breadth.

Conclusions:

• The proposed photonic heterostructure provides a viable route to achieving highly selective optical filters.
• The design strategy effectively controls the interplay between frequency and angular responses of defect modes.
• Further optimization of practical designs is suggested for real-world applications.