Gas Filling and Evacuation of Hollow-Core Optical Fibres through Laser-Machined Side Channels

Modifying the gas content inside hollow-core optical fibres can be used for reducing loss, optical nonlinearity, and phase noise, for modifying chromatic dispersion, or for gas sensing. However, filling or evacuating long lengths of fibres through the fibre ends is extremely slow. Here we report on our work on fluid-dynamics modelling of gas flow through laser machined holes in the fibre jacket to determine optimum hole sizes and hole spacings for fast filling and/or evacuation of hollowcore optical fibres.