Graphene photonic crystal fibre with strong and tunable light-matter interaction

The integration of photonic crystal fibre (PCF) with various functional materials has greatly expanded the application regimes of optical fibre(1-12). The emergence of graphene (Gr) has stimulated new opportunities when combined with PCF, allowing for electrical tunability, a broadband optical response and all-fibre integration ability(13-18). However, previous demonstrations have typically been limited to micrometre-sized samples, far behind the requirements of real applications at the metre-scale level. Here, we demonstrate a new hybrid material, Gr-PCF, with length up to half a metre, produced using a chemical vapour deposition method. The Gr-PCF shows a strong light-matter interaction with similar to 8 dB cm(-1) attenuation. In addition, the Gr-PCF-based electro-optic modulator demonstrates a broadband response (1,150-1,600 nm) and large modulation depth (similar to 20 dB cm(-1) at 1,550 nm) under a low gate voltage of similar to 2 V. Our results could enable industrial-level graphene applications based on this Gr-PCF and suggest an attractive platform for two-dimensional material-PCF.