Linearized fiber-optic link with a high spurious free dynamic range over a wide frequency range

Area of Science:

• Photonics and Optical Communications
• Electrical Engineering
• Signal Processing

Background:

• Traditional fiber-optic links often exhibit limited spurious free dynamic range (SFDR) over narrow frequency bands.
• Achieving high SFDR typically requires complex structures and electrical components, limiting practical applications.
• Third-order intermodulation distortion is a key challenge in maintaining linearity in optical links.

Purpose of the Study:

• To develop an all-optical linearized fiber-optic link with a high SFDR over an extended frequency range.
• To overcome the limitations of existing designs that restrict high SFDR to limited frequency bands.
• To present a simplified, cost-effective solution for high-performance optical links.

Main Methods:

• Utilized a dual-parallel Mach-Zehnder modulator (DPMZM) with a novel bias setting strategy.
• Controlled third-order intermodulation distortion by adjusting a single bias voltage of the DPMZM.
• Employed off-the-shelf components for bias stabilization to ensure consistent performance.
• Implemented an unamplified, all-optical link architecture.

Main Results:

• Achieved a high SFDR of 120.5 dB·Hz^4/5 ± 1.6 dB.
• Demonstrated this performance over a wide frequency range of 2-20 GHz.
• The linearized fiber-optic link exhibited a simple structure with no electrical components.
• Sustained high SFDR performance through bias stabilization techniques.

Conclusions:

• The proposed all-optical linearized fiber-optic link offers a significant advancement in achieving wideband high SFDR.
• The novel DPMZM bias control method simplifies the system while enhancing linearity.
• This technology provides a robust and practical solution for demanding optical communication applications.