Transmitter IQ Skew Calibration using Direct Detection

TL;DR

This paper introduces a low-cost, accurate method for calibrating transmitter IQ skew in coherent transceivers using direct detection, achieving high precision with minimal estimation errors.

Contribution

It is the first to utilize a direct detection-based feedback approach for coherent transmitter IQ skew calibration, enhancing calibration reliability and accuracy.

Findings

Estimation errors of +/-0.2ps achieved

Reliable calibration scheme demonstrated

Low-cost implementation proposed

Abstract

We propose a transmitter skew calibration based on direct detection of coherent signals with estimation errors of +/-0.2ps, providing a reliable, accurate and low-cost scheme to calibrate skew for coherent transceivers. In October 2019, this work was submitted / was exposed to Optical Fiber Communication Conference 2020 but an acceptance was not granted. We claimed the first time to use a direct detection-based feedback method for coherent transmitter calibration.