MBI staff member
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Johannes Tümmler

tuemmler@mbi-berlin .de

+49 30 6392 1311

Scientist

Member of Projects: 1.2


 

Research Topic


Short introduction:


The thin-disk laser technology is the key to laser systems delivering high pulse energy (several 100 mJ up to the Joule level) in combination with high repetition rate on the kHz level. At MBI we started the work on thin-disk lasers to setup a driver for an X-ray laser. We aimed at laser parameters of more than 500 mJ at 100 Hz repetition rate. As laser medium Yb doped YAG was chosen. The required fiber coupled pump laser diodes emitting at 940 nm wavelength were developed at the Ferdinand Braun Institut who was our partner in this project supported by Pro FIT . Further partners were the group of A. Giesen from the Institut für Strahlwerkzeuge (IFSW) as well as Trumpf Laser Technology and Dausinger & Giesen.
Motivated by the success of the first project the subsequent development step aimed at more than 1 Joule laser pulse energy. This project was financed by EFRE and SAW.
Several thin-disk laser amplifiers have been developed. The amplifier that has been set up most often is a regenerative amplifier. In this type of amplifier a very weak laser pulse of several nano-Joule pulse energy is amplified as long as an electro-optical switch opens the amplifier for the laser pulse to leave. The latest version of this amplifier can be used to amplify laser pulse to more than 300 mJ pulse energy at a repetition rate of 100 Hz. In general these regenerative amplifiers are used as pre-amplifiers. The laser pulses are then further amplified in a multi-pass or a ring amplifier. The multi-pass amplifiers we have set up could be operated with up to 500 mJ laser pulse energy. Also a ring amplifier had been developed amplifying a laser pulse to more than 1 J at 100 Hz repetition rate.
One of the most important element in thin-disk laser development is the thin-disk itself. A large portion of the time was invested in the manufacturing of the thin-disks. Since the laser beam is reflected from the backside of the disk the optical quality of the laser disk must be as good as the optical quality of a mirror, but the thin-disk is only a few hundred micrometer thick! Therefore, attaching the thin-disk to a heat-sink is a very sophisticated process.

 



Research Highlights


  • Regenerative amplifier emitting more than 300 mJ pulse energy at 100 Hz repetition rate.
  • Demonstration of more than 1 J pulse energy at 100 Hz repetition using a room-temperature ring amplifier rate.

Publications


Publications at MBI