Paper 14092-26
Paper 14092-26
Low-noise supercontinuum using a 1.85μm fs pump in elliptical-core and normal-dispersion ZBLAN fibres
14 April 2026 • 14:40 - 15:00 CEST | Churchill (Niveau/Level 1)
Abstract
We have developed a novel, low-noise 1.85 µm femtosecond (fs) pump delivering 58 fs pulses at 210 mW, with a 40 MHz repetition rate and a low relative intensity noise (RIN) of 0.41%. We identified two elliptical-core, polarisation-maintaining ZBLAN fibres with core dimensions of 6.7×2.7 µm and 8.9×4.1 µm that exhibit all-normal-dispersion in the region of interest. By pumping these fibres with the 1.85 µm source, we generated an ultra-low-noise supercontinuum (SC) in the 6.7×2.7 µm core fibre, spanning 1.500–2.251 µm at the −40 dB level, with a minimum RIN of 0.22% at 1.7 µm. The SC from the 8.9×4.1 µm core fibre spans 1.465–2.297 µm at the −40 dB level, with a minimum RIN of 0.36% at 2.0 µm. To achieve higher peak power, the 58 fs pulses were soliton-compressed to sub-10 fs durations. The resulting pulse was coupled into the 6.7×2.7 µm fibre, producing an ultra-low-noise SC spanning 0.771–2.724 µm, with a measured RIN as low as 0.21% at 2.1 µm.
Presenter
Shreesha Rao D. S.
Technical Univ. of Denmark (Denmark), Univ. of Bern (Switzerland)
Dr. Shreesha Rao D. S. is a postdoctoral researcher with the Fibre Sensors and Supercontinuum group at the Department of Electrical and Photonics Engineering, Technical University of Denmark. He received the DFF International Postdoctoral Fellowship from the Independent Research Fund Denmark and was a guest researcher at the University of Bern (2022–2024). He earned his Ph.D. from DTU in 2020 as a Marie Skłodowska-Curie ITN fellow, focusing on ultra-low-noise supercontinuum generation in normally dispersive fibres for shot-noise-limited ultra-high-resolution optical coherence tomography and broadband scanning near-field optical microscopy. In Aug–Sep 2020, he worked on noise studies using dispersive Fourier transform at CNRS-FEMTO-ST, France. Shreesha holds M.Tech. (Optoelectronics and Communication, Gold Medal), M.Sc. (Physics, Photonics), and B.Sc. (Physics, Honours) from Sri Sathya Sai Institute of Higher Learning and previously worked at IIT Madras on underwater laser communication