Fibre tapering using plasmonic microheaters and deformation-induced pull

Optical fibres with diameters at micro-or sub-micrometre scale are widely adopted as a convenient tool for studying light–matter interactions.To prepare such devices,two elements are indispensable:a heat source and a pulling force.In this paper,we report a novel fibre-tapering technique in which micro-sized plasmonic heaters and elaborately deformed optical fibres are compactly combined,free of flame and bulky pulling elements.Using this technique,micro-nano fibres with abrupt taper and ultra-short transition regions were successfully fabricated,which would otherwise be a challenge for traditional techniques.The compactness of the proposed system enabled it to be further transferred to a scanning electron microscope for in-situ monitoring of the tapering process.The essential dynamics of“heat and pull”was directly visualised with nanometre precision in real time and theoretically interpreted,thereby establishing an example for future in-situ observations of micro and nanoscale light-matter interactions.