Two-dimensional photonic quasicrystals by single beam computer-generated holography

Area of Science:

• Photonics and Materials Science
• Optics and Wave Phenomena

Background:

• Conventional periodic crystals lack symmetries beyond 6-fold rotational symmetry.
• Photonic quasicrystals offer unique properties due to their aperiodic nature and high rotational symmetries.
• Fabrication of complex quasicrystalline structures remains a significant challenge.

Purpose of the Study:

• To present a novel, single-beam fabrication technique for photonic quasicrystals.
• To demonstrate the capability of creating structures with symmetries not achievable by conventional methods.
• To explore the fabrication of specific aperiodic structures like Penrose tilings and Thue-Morse sequences.

Main Methods:

• Utilized a programmable Spatial Light Modulator (SLM) to encode Computer-Generated Holograms (CGHs).
• Employed a single-beam holographic technique for precise structure fabrication.
• Demonstrated fabrication of Penrose-tiled structures and a 2D Thue-Morse structure.

Main Results:

• Successfully fabricated Penrose-tiled photonic quasicrystals with up to 23-fold rotational symmetry.
• Created a two-dimensional Thue-Morse structure, an aperiodic pattern.
• The single-beam technique overcomes limitations of multi-beam holography for complex aperiodic structures.

Conclusions:

• The SLM-based CGH technique offers a versatile and powerful approach for fabricating advanced photonic quasicrystals.
• This method enables the creation of complex aperiodic structures with unprecedented symmetries.
• The demonstrated fabrication capabilities open new avenues for exploring the optical properties of quasicrystals.