Cross-talk-free, high extinction ratio, and ultra-compact all‑optical 4 × 2 encoder using graphene-based plasmonic...

Area of Science:

• Photonics and Optical Engineering
• Materials Science
• Nanotechnology

Background:

• Optical encoders are crucial components in modern communication systems.
• Graphene-plasmonic waveguides offer unique properties for integrated optics.
• Miniaturization and high performance are key challenges in optical device design.

Purpose of the Study:

• To propose and analyze an all-optical 4x2 encoder.
• To utilize graphene-plasmonic waveguides for efficient optical encoding.
• To investigate the performance of the encoder in the 8-12 μm wavelength range.

Main Methods:

• Design of a novel graphene-plasmonic waveguide structure.
• Simulation using the three-dimensional finite-difference time-domain (3D-FDTD) method.
• Analysis of geometric parameters and graphene chemical potential effects.

Main Results:

• The encoder operates effectively in the 8-12 μm range.
• Achieved a minimum extinction ratio (ERmin) of 19 dB at 10 μm.
• Reported low cross-talk (CT) of -21.3 dB and insertion loss (IL) of -1.31 dB.
• Demonstrated an ultra-compact footprint of 4.25 μm².

Conclusions:

• The proposed graphene-plasmonic encoder offers high performance and miniaturization.
• Its characteristics make it suitable for advanced communication and signal processing.
• This work advances the development of integrated photonic devices.