The all-optical modulator in dielectric-loaded waveguide with graphene-silicon heterojunction structure

Area of Science:

• Photonics and Materials Science
• Optoelectronics
• Nanotechnology

Background:

• All-optical modulators are crucial for on-chip optical interconnects, but their performance is often limited by fiber-graphene interactions, hindering high integration.
• Existing designs face challenges in achieving efficient light-matter interaction for practical applications.

Purpose of the Study:

• To propose and experimentally demonstrate a novel all-optical modulator utilizing a graphene-silicon heterojunction (GSH) within a dielectric-loaded waveguide (DLW).
• To enhance light-graphene interaction for improved modulation performance and enable compact, highly integrated photonic devices.

Main Methods:

• Fabrication of a dielectric-loaded waveguide (DLW) structure integrated with a graphene-silicon heterojunction (GSH).
• Experimental characterization of the all-optical modulator's performance under specific modulation and communication light wavelengths and power.
• Analysis of the enhanced light-graphene interaction due to the DLW structure and GSH tuning of graphene Fermi energy.

Main Results:

• The proposed DLW-GSH structure significantly enhances light-graphene interaction.
• An experimental modulation efficiency of 0.0275 dB µm^-1 was achieved at a communication wavelength of 1.55 µm using 532 nm modulation light (60 mW).
• The modulator exhibits a compact footprint, essential for high integration.

Conclusions:

• The developed all-optical modulator based on DLW and GSH offers a promising solution for high-performance on-chip optical interconnects.
• This design overcomes previous limitations by enhancing light-graphene interaction and enabling efficient modulation.
• The compact nature of the device makes it a strong candidate for future highly integrated photonic systems.