The laser system of the TeWaTi laboratory consists of a Ti:sapphire-based double chirped pulse amplifier (CPA). The seed beam is generated by a Femtoslasers Rainbow CEP4 Ti:sapphire oscillator, which provides carrier envelope phase (CEP) stabilized, 7 fs long ultrashort pulses with 75 MHz repetition rate and spectral range from 650 nm to 950 nm. The CEP stabilization is provided by the state-of-the-art “feedforward” technology, which keeps the CEP-noise under 50 mrad. The seed pulses from the oscillator immediately enter into the first multi-pass CPA amplifier stage. The pulses travel through the Ti:sapphire amplifier crystal ten times, which is pumped by a diode-pumped Nd:YLF laser manufactured by Photonics Industries. This pump laser provides 20 mJ pulses at 527 nm with a repetition rate of 200 Hz; and its outstanding, 0.2% energy stability translates to the amplified short pulses as well. An acousto-optical dispersion filter (Fastlite Dazzler) is implemented in the system in order to effectively fine-tune of the dispersion of the pulses and also to compensate the spectrum narrowing, which is a side effect of
the amplification. At the output of the preamplifier stage we have 1.5 mJ, 25 fs pulses at 200 Hz repetition rate.

The power amplifier stage aims to the terawatt peak power regime. In a five-pass geometry, the preamplified pulses are amplified further up to 50 mJ, pumped by 500 mJ pulses at 532 nm with 10 Hz repetition rate from a flash lamp based Spectra Physics Quanta Ray Nd:YAG. After the output of the compressor of the power amplifier stage, the pulse duration is still under 30 fs. 

In the past few years besides laser development, we also updated the diagnostics inventory in the laboratory (e.g. TOF electron spectrometer, Wizzler pulse characterization device, GHz oscilloscope etc.). Furthermore, we established ISO 7 class cleanroom and expanded our safety system and equipment.