We produce 1.5 cycle (10.5 fs), 1.2 mJ, 3 kHz carrier-envelope-phase-stable pulses at 2.1 μm carrier wavelength, from a three-stage optical parametric chirped-pulse amplifier system, pumped by an optically synchronized 1.6 ps Yb:YAG thin disk laser. A chirped periodically poled lithium niobate crystal is used to generate the ultrabroad spectrum needed for a 1.5 cycle pulse through difference frequency mixing of spectrally broadened pulse from a Ti:sapphire amplifier. It will be an ideal tool for producing isolated attosecond pulses with high photon energies.
Carrier-envelope-phase-stable, 1.2 mJ, 1.5 cycle laser pulses at 2.1 mu m
Yunpei Deng,
Alexander Schwarz,
Hanieh Fattahi,
Moritz Ueffing,
Xun Gu,
Marcus Ossiander,
Thomas Metzger,
Volodymyr Pervak,
Hideki Ishizuki, et al.
Optics Letters
37
(23)
4973-4975
(2012)
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We report on an active synchronization between two independent mode-locked lasers using a combined electronic-optical feedback. With this scheme, seed pulses at MHz repetition rate were amplified in a non-collinear optical parametric chirped pulse amplifier (OPCPA). The amplifier was seeded with stretched 1.5 nJ pulses from a femtosecond Ti:Sapphire oscillator, while pumped with the 1 ps, 2.9 µJ frequency-doubled output of an Yb:YAG thin-disk oscillator. The residual timing jitter between the two oscillators was suppressed to 120 fs (RMS), allowing for an efficient and broadband amplification at 11.5 MHz to a pulse energy of 700 nJ and an average power of 8 W. First compression experiment with 240 nJ amplified pulse energy resulted in a pulse duration of ~10 fs.
The development of new high power laser sources tends toward optical parametric chirped pulse amplification (OPCPA) in recent years. One of the difficulties in OPCPA is the the temporal overlap between pump and seed pulses. In this work we characterize our timing jitter on a single-shot basis using spectrally resolved cross-correlation in combination with a position sensitive detector. A commercial beam stabilization is adapted to actively enhance temporal overlap. This delay-stabilizer reduces the RMS jitter from σ = 127fs down to σ = 24fs. The enhanced temporal overlap is demonstrated in our frontend and we propose the scheme to be applicable in many optically synchronized high-repetition-rate OPCPA systems.
Kontakt
Forschungsgruppe Hanieh Fattahi
Max-Planck-Institut für die Physik des Lichts Staudtstr. 2 91058 Erlangen
