Abstract
We investigate soliton self-compression and ultraviolet resonant dispersive wave emission in the higher-order modes of a gas-filled hollow capillary fibre (HCF). Our simple analytical scaling rules predict shorter required waveguides and different energy scales when moving from the fundamental to higher-order modes. Experimentally, we demonstrate soliton self-compression and ultraviolet dispersive wave emission in the double-lobe LP11 mode of an argon-filled HCF, which we excite by coupling into the fibre at oblique incidence. We observe the generation of ultraviolet dispersive waves which are frequency-shifted and more narrowband as compared to fundamental-mode generation due to the stronger modal dispersion, and a suppression of the supercontinuum between the dispersive wave and the pump pulse. With numerical simulations, we confirm the predictions of our scaling rules and find that the use of higher-order modes can suppress photoionisation and plasma effects even while allowing for much higher pulse energy to be used in the self-compression process. Our results add another degree of freedom for the design of hollow-waveguide systems to generate sub-cycle field transients and tuneable ultrashort laser pulses.
Original language | English |
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Article number | 034002 |
Journal | JPhys Photonics |
Volume | 4 |
Issue number | 3 |
Early online date | 23 May 2022 |
DOIs | |
Publication status | Published - Jul 2022 |
Keywords
- dispersive wave emission
- frequency conversion
- hollow-core fibres
- multi-mode nonlinear optics
- ultrafast optics
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering