Single-to-dual channel wavelength conversion of picosecond pulses using PPLN-based double-ring fibre laser

Proposed and demonstrated is a novel single-to-dual channel wavelength conversion of picosecond pulses based on cascaded second-order nonlinear interaction by use of a double-ring fibre laser incorporating a periodically poled lithium niobate (PPLN) waveguide. No external pumps are required. The results imply that it is possible to realise tunable single-to-multiple channel wavelength conversion with multichannel lasing pumps employed.