Five Orders of Cascaded Raman Fibre Laser Oscillation From 1550 nm to Mid‐IR at 2334 nm Wavelength

We demonstrate a cascaded Raman fibre laser (RFL) oscillation up to the fifth order Stokes wave, from ∼1550 nm to mid‐IR at 2334 nm, with silica fibres. The pumping was done with an amplified spontaneous emission (ASE) light of erbium‐doped fibre (EDF) in the 1550 nm wavelength regime. The low orders (first to third) could be easily obtained in continuous wave (CW) mode, while the fourth and fifth orders were obtained in a pulse mode. We used highly nonlinear fibres that allowed relatively short fibre cavity lengths of (10‐100)m.