Broadband high dynamic range fiber optic link based on a dual-polarization modulator

Area of Science:

• Photonics and Optical Engineering
• Radio Frequency (RF) Systems

Background:

• Nonlinearity in fiber-optic links limits spurious free dynamic range (SFDR).
• Existing linearization techniques often require complex electrical components or parameter tuning.

Purpose of the Study:

• To present a simple, linearized fiber-optic link with high SFDR.
• To demonstrate linearization without electrical components or parameter readjustment.

Main Methods:

• Utilized a commercial dual-polarization modulator followed by a linear polarizer.
• Designed the polarizer angle to cancel third-order intermodulation distortion.
• Performed theoretical analysis, photonic simulation, and experimental verification.

Main Results:

• Achieved SFDR exceeding 124 dB·Hz^4/5 over a 2-18 GHz bandwidth.
• Demonstrated an SFDR of 127.3 dB·Hz^4/5 with an optical amplifier.
• Confirmed performance across various RF input frequencies without system readjustment.

Conclusions:

• The proposed dual-polarization modulator-based link offers a robust and efficient method for linearization.
• This optical linearization technique achieves state-of-the-art SFDR performance.
• The simplicity and effectiveness make it suitable for advanced RF photonics applications.