Self-focusing below the critical power in gas-filled hollow-core PCF

Abstract

Nonlinear optics in fibres has for decades been carried out predominantly in step-index glass cores that support just one transverse mode, or if the core supports higher-order modes (HOMs), careful launch alignment is used to minimize their excitation in practice. In gas-filled hollow-core fibres, however, single-mode propagation ceases to be valid at high… (More)