Linearization of a dual-parallel Mach-Zehnder modulator using optical carrier band processing

TL;DR

This paper presents a method to linearize a dual-parallel Mach-Zehnder modulator in microwave photonics, achieving significant distortion suppression and enabling simultaneous multi-signal modulation without extra RF components.

Contribution

It introduces a novel linearization technique using optical carrier band processing, validated through theoretical analysis and experimental demonstration.

Findings

17 dBm suppression of third-order distortion

3 dB improvement in sideband suppression ratio

Enables simultaneous modulation of four signals without additional RF components

Abstract

The linearization of a microwave photonic link based on a dual-parallel Mach-Zehnder modulator is theoretically described and experimentally demonstrated. Up to four different radio frequency tones are considered in the study, which allow us to provide a complete mathematical description of all third-order distortion terms that arise at the photodetector. Simulations show that a complete linearization is obtained by properly tuning the DC bias voltages and processing the optical carrier and. As a result, a suppression of 17 dBm is experimentally obtained for the third-order distortion terms, as well as a SDFR improvement of 3 dB. The proposed linearization method enables the simultaneous modulation of four different signals without the need of additional radio frequency components, which is desirable to its implementation in integrated optics and makes it suitable for several applications in microwave photonics.