Deep THz modulation at Fabry-Perot resonances using graphene in periodic microslits

Area of Science:

• Optoelectronics
• Terahertz (THz) Technology
• Materials Science

Background:

• Terahertz (THz) radiation offers large bandwidths for high-speed communication, including frequency hopping technology.
• Effective THz modulators are essential for encoding information onto carrier waves but are currently limited.
• Existing THz modulators often lack the deep and stable modulation required across various frequencies.

Purpose of the Study:

• To propose and demonstrate a novel THz modulator design.
• To achieve deep and stable modulation at multiple THz frequencies.
• To enhance performance beyond existing THz modulator technologies.

Main Methods:

• Integration of a periodic metal microslit structure with a Fabry-Perot resonance (MS-FP) structure.
• Utilizing a non-resonant field enhancement effect within the microslits.
• Development of new equations to characterize the MS-FP modulator's performance.

Main Results:

• Achieved >95% modulation depth using a SiO2/Si gated graphene device.
• Demonstrated performance across 14 Fabry-Perot resonant frequencies.
• Covered a bandwidth of 1.4 THz, significantly outperforming previous modulators.

Conclusions:

• The novel MS-FP THz modulator design significantly enhances modulation depth and bandwidth.
• This technology shows great promise for advancing high-speed terahertz communication systems.
• The developed modulator surpasses the performance of recently reported similar structures.