Polymerized micro-patterned optical birefringence film and its fabrication using multi beam mixing

Area of Science:

• Materials Science
• Optics
• Polymer Science

Background:

• Photo-polymerized liquid crystal (LC) films rely on photo-alignment layers for controlled molecular orientation.
• Optimizing UV light exposure parameters is crucial for achieving desired optical properties and stability in LC films.

Purpose of the Study:

• To investigate the effect of UV light polarizability on the alignment of liquid crystal (LC) films on photo-alignment layers.
• To determine the optimal UV polarizability for fabricating high-performance micro-patterned optical birefringence films (MP-OBFs).

Main Methods:

• Investigating photo-polymerized LC films with varying UV light polarizability on photo-alignment layers.
• Fabricating micro-patterned optical birefringence films (MP-OBFs) using an incoherent multi-beam mixing method with spatially modulated UV polarization.
• Utilizing a two-beam mixing method to create a simple MP-OBF.

Main Results:

• Low UV light polarizability (down to 0.1) is sufficient to induce bulk LC alignment.
• UV light with polarizability greater than 0.3 resulted in outstanding optical performance.
• Films fabricated with low polarizability light showed comparable thermo-stability to those made with high polarizability light.
• A fabricated MP-OBF using a two-beam mixing method demonstrated quality 3D film performance.

Conclusions:

• The study demonstrates that UV light polarizability significantly impacts the optical performance and alignment of photo-polymerized LC films.
• A novel method using incoherent multi-beam mixing allows for spatial modulation of UV light polarization, enabling the fabrication of MP-OBFs.
• This technique offers a promising approach for creating advanced optical components like MP-OBFs, optical retarders, and polarization gratings.