# Coherent optical modulation of partially mode-locked fiber laser based on coherent population oscillation in reduced oxide graphene

## TL;DR

This paper demonstrates a novel, efficient method for coherently controlling partially mode-locked fiber lasers using reduced graphene oxide, significantly reducing the required control laser power.

## Contribution

It introduces the first experimental demonstration of coherent population oscillation in reduced graphene oxide for optical modulation of fiber lasers, enabling lower power control.

## Key findings

- Significant depression/enhancement of sidebands observed
- Effective manipulation of mode-locked fiber laser achieved
- Phase variation induced is highly asymmetrical

## Abstract

Optical control of graphene-based photonic devices and systems has been under extensive explorations, nevertheless, the requirement of high power pump laser due to incoherent modulation makes those schemes low efficient. Here, we demonstrate coherent manipulation of the operating states of partially mode-locked fiber laser based on coherent population oscillation in reduced graphene oxide for the first time. We couple a much weaker continuous wave laser into the resonator operating with parametric instability state, and observe significant depression/enhancement of the sidebands when the coherent population oscillation conditions are satisfied. Besides, significant depression of partially mode-locked fiber laser is achieved. The experimental results reveal that the coherent population oscillation in reduced graphene oxide is highly effective in manipulating mode-locked fiber laser system, and the induced phase variation is highly asymmetrical. The discovery of coherent population oscillation in reduced graphene oxide facilitates coherent optical modulation of reduced graphene oxide-based photonic devices and systems with a much weaker controlling laser.

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Source: https://tomesphere.com/paper/1902.05901