Picosecond holmium fibre laser pumped at 1125 nm

We report a passively mode-locked, all-fibre holmium laser based on nonlinear polarisation rotation. As a pump source use is made of an 1125-nm ytterbium-doped fibre laser. The pulse repetition rate of the holmium laser is 7.5 MHz, and the pulse duration does not exceed 52 ps at wavelengths of 2065 and 2080 nm. The average laser output power reaches 5 mW.