Tunable broadband polarization converters based on coded graphene metasurfaces

Area of Science:

• Photonics and Metamaterials
• Computational Electromagnetics
• Materials Science

Background:

• Polarization converters are crucial optical components.
• Metasurfaces offer novel ways to manipulate light polarization.
• Graphene's tunable properties are ideal for reconfigurable devices.

Purpose of the Study:

• To design broadband polarization converters using coded metasurfaces.
• To explore the use of optimization algorithms for metasurface design.
• To investigate graphene's role in tunable optical devices.

Main Methods:

• Employed randomly initialized hill climbing and genetic algorithms for optimization.
• Utilized a pixeled graphene patch with an elliptic structure as the initial design.
• Investigated the impact of graphene's chemical potential, relaxation time, and incident angle.

Main Results:

• Successfully designed four broadband polarization converters.
• Demonstrated that graphene's chemical potential tunes the operating frequency.
• Analyzed the influence of relaxation time and incident angle on bandwidth.

Conclusions:

• Optimization algorithms are effective for designing coded metasurface polarization converters.
• Graphene-based metasurfaces provide tunable and broadband polarization conversion.
• The designed converters show potential for various optical applications.