Highly linear wavelength-tunable microring-assisted Mach-Zehnder modulator.

Area of Science:

• Photonics
• Optical Communications
• Materials Science

Background:

• Nonlinearities in optical modulators limit performance.
• Wavelength tunability is crucial for flexible optical networks.
• Graphene offers unique electro-optic properties for device enhancement.

Purpose of the Study:

• To propose and analyze a wavelength-tunable microring-assisted Mach-Zehnder modulator (MRAMZM) using graphene.
• To suppress second- and third-order nonlinearities for improved linearity.
• To achieve enhanced spurious-free dynamic range (SFDR).

Main Methods:

• Integration of graphene onto a racetrack microring for wavelength tunability and controlled loss.
• Analysis of modulation characteristics considering microring loss.
• Utilizing a graphene-embedded asymmetric coupling structure to control coupling efficiency.

Main Results:

• Achieved wavelength tunability and suppressed nonlinearities.
• Improved device linearity over a 2 nm range (1.5543 to 1.5562 µm).
• Demonstrated a spurious-free dynamic range third-order intermodulation distortion of approximately 114 dB·Hz²/³.

Conclusions:

• The proposed graphene-based MRAMZM effectively suppresses nonlinearities.
• The device offers improved linearity and high SFDR, suitable for advanced optical systems.
• Graphene integration provides a viable path for tunable and linear optical modulators.