Frequency-time coherence for all-optical sampling without optical pulse source

TL;DR

This paper introduces a simple all-optical sampling method leveraging frequency-time coherence and coupled modulators, eliminating the need for optical pulse sources like mode-locked lasers, with tunable parameters for enhanced flexibility.

Contribution

The paper presents a novel all-optical sampling technique using coupled modulators driven by an electrical sine wave, simplifying implementation and enabling tunable bandwidth, repetition rate, and time shift.

Findings

Enables all-optical sampling without optical pulse sources.

Uses only two coupled modulators driven electrically.

Provides electrically tunable sampling parameters.

Abstract

Sampling is the first step to convert an analogue optical signal into a digital electrical signal. The latter can be further processed and analysed by well-known electrical signal processing methods. Optical pulse sources like mode-locked lasers are commonly incorporated for all-optical sampling, but have several drawbacks. A novel approach for a simple all-optical sampling is to utilise the frequency-time coherence of each signal. The method is based on only using two coupled modulators driven with an electrical sine wave, allowing simple integration in appropriate platforms, such as Silicon Photonics. The presented method grants all-optical sampling with electrically tunable bandwidth, repetition rate and time shift.