Professor Poletti’s interests include nonlinear optical effects in fibres, photonic bandgaps, light resonances as optical guidance mechanisms, direct and inverse fibre design, fluid dynamics models of fibre fabrication, loss mechanisms and intermodal effects in optical fibres and optical communications, as well as the development of novel nonlinear, polarisation maintaining and active optical fibres.

Over the years, Prof Poletti had his group have led many world-record-setting experiments based on HCFs, which he has personally presented at 8 post-deadline sessions at the premier optical communications conferences, ECOC and OFC. These include the first demonstration of wavelength division multiplexing (WDM) transmission in an HCF [1], the highest data transmission capacity in an HCF (70Tbit/s) and the longest single span transmission (11km).

More recently, he has proposed a novel HCF fibre concept, the Nested Antiresonant Nodeless Fibre (NANF) , based on which in 2020 his Southampton group has achieved the lowest reported optical loss in any HCF (0.28 dB/km), and the longest data transmission distance through a hollow-core fibre, in collaboration with colleagues at Politecnico di Torino (772km).

NANFs have proved capable of maintaining the polarisation purity of in incoming beam with a fidelity orders of magnitude higher than the best solid core polarization maintaining fibre, and their loss at technologically relevant wavelengths in the visible, around 850nm and 1060nm is already comparable or slightly lower than solid core silica fibre can possibly achieve.