Nano-lithographically fabricated titanium dioxide based visible frequency three dimensional gap photonic crystal

Area of Science:

• Materials Science
• Optics and Photonics

Background:

• Photonic crystals (PCs) are crucial for light manipulation, with complete 3D photonic band gaps offering ultimate light control.
• Fabricating visible-light PCs with high refractive index materials and nanoscale precision remains a significant challenge.
• Existing methods struggle to integrate materials and achieve the required long-range order for visible frequencies.

Purpose of the Study:

• To demonstrate a nanolithography approach for fabricating visible-light photonic crystals.
• To investigate the potential for achieving a complete 3D photonic band gap in titania woodpile structures.
• To enable the development of advanced photonic devices operating at visible wavelengths.

Main Methods:

• Utilized a multilevel electron beam direct write lithography technique.
• Employed physical vapor deposition for material integration.
• Fabricated four-layer titania woodpile photonic crystals with nanoscale precision.

Main Results:

• Successfully fabricated titania woodpile photonic crystals with a 300nm lattice constant.
• Achieved a short wavelength bandedge of 525nm, indicating potential for a 3D photonic band gap.
• Demonstrated nanoscale precision and defect control capabilities of the fabrication method.

Conclusions:

• The demonstrated nanolithography approach is a significant step toward realizing visible-light photonic crystals.
• This method facilitates the creation of PCs with potential for complete 3D photonic band gaps.
• The developed technique paves the way for novel photonic devices in lighting, lasers, sensing, and biophotonics.