Research scientists from the Fraunhofer Institute for Laser Technology ILT in Aachen have installed a femtosecond laser at the Max Planck Institute of Quantum Optics MPQ in Garching, as part of the Korona cooperation. The project claims it is the first ever laser to generate an average power of 280W at 515nm wavelength with perfect beam quality. The turn-key laser is based on a Yb:Innoslab amplifier with frequency doubling. It is claimed that no other laser system has ever offered more output with diffraction-limited beam quality in the visible spectral range.
Ultrashort laser pulses are an established tool in science and industry. In many areas, the range of applications can be expanded by scaling them up to high average output power. In recent years, beam source development has seen great progress on this front. Average output power of several hundred Watts with diffraction-limited beam quality have been demonstrated using Ytterbium-doped laser media at 1µm wavelength in fibre, Innoslab and thin-disk geometry. The Fraunhofer ILT scientists hold the record with their Yb:Innoslab amplifier, generating an output power of 1.1 kW.
These beam sources must be reliable and easy to operate if they are to be used widely in science and industry. The scientists from Fraunhofer ILT have installed a laser system at the MPQ, which delivers an average power of 280W at 515nm wavelength and an almost diffraction-limited beam quality of M² < 1.4 using near-industrial construction and user interface. It works by amplifying the radiation from a commercial femtosecond laser with 3W output power in a Yb:Innoslab amplifier to 470W at a pulse duration of 700fs and then doubling its frequency in a non-linear crystal. As a result, the scientists at the MPQ have an average power at their disposal, which is one magnitude higher than that generated by commercially available systems.