Ultrahigh-linearity dual-drive scheme using a single silicon modulator

Area of Science:

• Photonics
• Electrical Engineering
• Materials Science

Background:

• High linearity is crucial for advanced microwave photonic links (MPLs).
• Silicon Mach-Zehnder modulators (MZMs) are key components in MPLs but suffer from nonlinearities.
• Existing single-drive schemes have limitations in achieving superior linearity.

Purpose of the Study:

• To present a high-linearity dual-drive scheme for silicon Mach-Zehnder modulators.
• To demonstrate the cancellation of nonlinear responses through optimized driving conditions.
• To achieve a record-breaking spurious-free dynamic range (SFDR) for silicon modulators.

Main Methods:

• Utilizing a single silicon dual-drive Mach-Zehnder modulator.
• Precisely adjusting bias voltages and radio frequency (RF) amplitudes of the two driving arms.
• Implementing a scheme where the interferometer's transfer function nonlinearity cancels the arms' nonlinear response.

Main Results:

• Achieved a spurious-free dynamic range (SFDR) of 123.4 dB·Hz^6/7 for third-order intermodulation distortion.
• This SFDR value is a record for silicon modulators.
• The conventional single-drive scheme yielded an SFDR of 102.6 dB·Hz^2/3 for comparison.

Conclusions:

• The proposed dual-drive scheme significantly enhances modulator linearity.
• This approach simplifies modulator design and improves performance.
• It paves the way for high-performance microwave photonic links.