Finite-difference time-domain simulation of a liquid-crystal optical phased array.

Area of Science:

• Optics and Photonics
• Materials Science
• Computational Physics

Background:

• Optical phased arrays (OPAs) are crucial for beam steering applications.
• Modeling OPAs with elements close to the wavelength of light presents significant challenges.
• Liquid crystal (LC) materials offer unique electro-optic properties for OPA development.

Purpose of the Study:

• To develop and demonstrate an accurate modeling method for high-resolution, liquid-crystal-based optical phased arrays (LC-OPAs).
• To extend modeling capabilities to LC-OPAs with array element sizes approaching the wavelength of light.
• To validate the simulation method by comparing calculated diffraction efficiency with experimental data.

Main Methods:

• Calculating the equilibrium liquid-crystal (LC) director field, incorporating fringing electric fields for small array elements.
• Utilizing a finite-difference time-domain (FDTD) method extended for birefringent materials to compute light transmission.
• Simulating diffraction efficiency for a test device and comparing it with experimental results.

Main Results:

• Demonstrated accurate modeling of high-resolution LC-OPAs.
• Successfully extended modeling to sub-wavelength array element sizes.
• Validated the simulation's predictive capability through comparison with experimental diffraction efficiency.

Conclusions:

• The developed modeling approach provides accurate simulations for LC-OPAs, particularly for challenging small element sizes.
• This method is extendable to various LC-OPA designs and operating conditions.
• The accurate modeling facilitates the design and optimization of advanced optical beam steering systems.