Switchable beam steering with zenithal bistable liquid-crystal blazed gratings

Area of Science:

• Optics and Photonics
• Materials Science
• Liquid Crystal Displays

Background:

• Zenithal bistable liquid crystal (LC) gratings offer unique optical properties.
• Switchable beam steering is crucial for advanced optical systems.
• Controlling LC orientation is key to device functionality.

Purpose of the Study:

• To design and theoretically investigate switchable beam steerers based on zenithal bistable LC gratings.
• To analyze the nematic orientation profiles and optical transmittance.
• To demonstrate high diffraction efficiency beam steering.

Main Methods:

• Tensorial formulation of the Landau-de Gennes theory for nematic orientation.
• Full-wave finite-element-method for optical transmittance calculations.
• Grating geometry design for optimized beam steering.

Main Results:

• High diffraction efficiency beam steering demonstrated between two stable LC states.
• Calculated spectral operation windows exceeding 50 nm in the visible spectrum.
• Beam steering efficiency maintained above 90% within these windows.

Conclusions:

• Zenithal bistable LC gratings are effective for switchable beam steering.
• Device performance shows tolerance to material parameter variations.
• The proposed gratings are suitable for visible light applications requiring high efficiency.