Tunable Fiber Source Produces 30-nJ Pulses

Researchers at Tampere University of Technology's Optoelectronics Research Centre in Tampere, Finland, have achieved 30-nJ pulse energies from an Yb-doped core-pumped fiber laser and a cladding-pumped double-clad fiber amplifier. The team noted that the performance of the tunable emitter, which operates at wavelengths between 980 and 1105 nm, may enable it to be employed in applications that are currently reserved for femtosecond Ti:sapphire lasers.

The setup's mode-locked master laser featured a length of Yb-doped fiber, a GaInNAs saturable absorber reflector that ensured self-starting operation and a tilting high-reflectivity mirror that enabled tunability.

A 915-nm diode laser served as the pump source. The fiber amplifier comprised a 50-cm-long all-glass fiber with 50-µm pump cladding and was pumped by a 4-W diode laser.