Multiple higher-order stop gaps in infrared polymer photonic crystals

Area of Science:

• Photonics
• Materials Science
• Optics

Background:

• Photonic crystals are crucial for controlling light.
• Miniaturization of photonic crystals presents challenges.
• Engineering stop gaps offers an alternative pathway for light manipulation.

Purpose of the Study:

• To explore femtosecond laser microfabrication for creating polymer photonic crystals.
• To investigate the generation of large and higher-order photonic band gaps.
• To analyze the spectral properties and tunability of these engineered structures.

Main Methods:

• Utilizing femtosecond laser microfabrication to create highly correlated void channel polymer microstructures.
• Fabricating woodpile polymer structures with varying unit cells.
• Characterizing the optical properties in the mid- and near-infrared spectral regions.

Main Results:

• Achieved photonic crystals with large stop gaps and numerous higher-order gaps in the mid- and near-infrared.
• Observed that gap wavelengths adhere to Bragg's law.
• Demonstrated tunability of higher-order gaps by modifying the woodpile structure, showing transitions from Bragg scattering to total reflection.

Conclusions:

• Femtosecond laser microfabrication is effective for engineering photonic crystals with significant stop gaps.
• The fabricated structures provide a viable alternative to miniaturization for photonic crystal applications.
• Tunable photonic properties, including higher-order gaps, can be achieved through structural modifications.