Polarization-dependent all-optical modulator with ultra-high modulation depth based on a stereo graphene-microfiber structure

TL;DR

This paper presents a polarization-dependent all-optical fiber modulator using a stereo graphene-microfiber structure, achieving ultra-high modulation depth and efficiency suitable for ultrafast optical signal processing.

Contribution

It introduces a novel stereo graphene-microfiber design with a spring-like geometry that significantly enhances modulation depth and efficiency over existing graphene-based modulators.

Findings

Achieved a modulation depth of ~7.5 dB for one polarization.

Demonstrated a modulation efficiency of ~0.2 dB/mW.

Enabled quick switching between transparent and opaque states.

Abstract

We report an in-line polarization-dependent all-optical fiber modulator based on a stereo graphene-microfiber structure (GMF) by utilizing the lab-on-rod technique. Owing to the unique spring-like geometry, an ultra-long GMF interaction length can be achieved, and an ultra-high modulation depth (MD) of ~7.5 dB and a high modulation efficiency (ME) of ~0.2 dB/mW were demonstrated for one polarization state. The MD and ME are more than one order larger than those of other graphene-waveguide hybrid all-optical modulators. By further optimizing the transferring and cleaning process, the modulator can quickly switch between transparent and opaque states for both the two polarization states with a maximized MD of tens of decibels. This modulator is compatible with current fiber-optic communication systems and may be applied in the near future to meet the impending need for ultrafast optical signal processing.