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Logo: Institut für Quantenoptik/Leibniz Universität Hannover
Logo Leibniz Universität Hannover
Logo: Institut für Quantenoptik/Leibniz Universität Hannover
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Ultrafast Lasers

There is a secret world beyond our perception where things happen much faster than our wits. Scientists over all the centuries invented machines and techniques to reveal the quickly evolving world of matter, molecules, and atoms. The latest and most successful achievements are the ultrafast lasers with time resolution in the femto- and attosecond regime. In the foci of commercially available high power laser pulses we are able to observe extreme conditions: Peak powers in the Terawatt, magnetic fields with thousands of Tesla, light pressures of Gigapascal, and temperatures of Megakelvin. In our group we study the physics of these laser sources; we investigate very new ways to control the photons, and many of our laser light sources here in Hannover are unique in the world. 

Parametric Oscillators and Amplifiers 

When the electric field in a laser pulse becomes comparable to the intra atom field strengths in matter, the electron motion becomes inharmonic, and nonlinear optical phenomena such as frequency doubling or sum- and difference frequency mixing can be observed. With high power ultrafast lasers these effects can be driven very efficiently, opening up the world of parametric oscillators and amplifiers as laser light sources with very special properties. More…

Ultrafast Solid State-Oscillators and Amplifiers

It was about 50 years ago, at the very beginning of laser physics, that scientists realized the tremendous potential of this source for generating ultrashort light pulses with unique properties and applications. Scientists and engineers invented the different concepts of Q-switching and mode-locking, and already in 1970, pulses with picosecond durations have been demonstrated from dye lasers. In the late eighties the impressive road of success of solid-state laser materials started (see figure), beginning with neodymium doped crystals, exploring the potential of chromium doped materials, and finally, in the early two-thousands, the pulses emitted from Ti:sapphire oscillators reached durations close to the single optical cycle. Meanwhile, a whole bunch of different broad-band solid-state laser materials have been explored, covering the range from the near UV to the near infrared. Still, the most prominent laser material for the generation of femtosecond pulses in the few-cycle range is Ti:sapphire, because of the large gain bandwidth, the large heat conductivity, and the reliably available high crystal quality. Regarding to high power laser light generation, Yb doped materials became the most important gain media due to the availability of high brightness semiconductor pump lasers and due to the small quantum defect. More…

Fiber Oscillators and Amplifiers

Based on wave guiding effects ultrafast fiber lasers offer a high potential for very stable and compact laser sources. More...