Thin-disk pumped optical parametric chirped pulse amplifier delivering CEP-stable multi-mJ few-cycle pulses at 6 kHz

Abstract

We present an optical parametric chirped pulse amplifier (OPCPA) delivering CEP-stable ultrashort pulses with 7 fs, high energies of more than 1.8 mJ and high average output power exceeding 10 W at a repetition rate of 6 kHz. The system is pumped by a picosecond regenerative thin-disk amplifier and exhibits an excellent long-term stability. In a proof-of-principle experiment, high harmonic generation is demonstrated in neon up to the 61 order.

Advanced industrial laser systems and applications

“…Ti:Sa: Titaniumsapphire oscillator, Regen: regenerative amplifier, BS: beam splitter, WP: waveplate, TFP: thin-film polarizer, SHG: second harmonic generation, PSS: pump-seed synchronization, FS: fused silica stretcher, OPA: optical parametric amplifier, CEP slow loop: carrier-envelope phase slow-loop stabilization, DCM: double-chirped mirror compressor. 19 In case of fulfilling phase matching conditions, one can drive the process of optical parametric amplification in the BBO crystal quite efficiently, without suffering the problem of spectral clipping as experienced in Yb:YAG at such pulse durations. Once the energy is transferred from the ps pump laser to the stretched fs laser pulse by the OPA process, which requires a precise temporal overlap of the pump and signal pulse in the BBO crystal, the amplified pulse can be recompressed in a grating compressor to its initial pulse duration of a couple fs.…”

Quasi-Parametric Chirped-Pulse Amplification Simultaneously Enables High Peak Power and High Average Power

“…In addition, a high laser repetition rate is also favorable to avoid the space-charge effect in applications such as photoelectron spectroscopy [11]. Drive lasers with a both high peak power (>100 TW) and a high repetition rate (>100 Hz) are becoming increasingly attractive for strong-field physics [12]- [18].…”

“…To achieve efficient conversion from the pump to the signal wave, the phase matching (PM) condition should be satisfied in OPCPA, i.e., k = k p -k s -k i = 0, where k p , k s , and k i are the wave vectors of the pump, signal, and idler waves, respectively. The required PM condition is usually realized with the aid of birefringence in nonlinear optical crystals, such as β-BBO [16]- [18], LBO [6], [25], and YCOB crystals [26], [27]. Heating of the crystal will change the refractive index and hence the PM condition [ Fig.…”

Ultrafast mid-IR fiber laser

“…Referring to the pulse energy scaling, the fiber laser have inherent ceiling compared with solid lasers [111][112][113] due to the small mode field area (< 3300 µm 2 [97]) and long active length (meter level). Even with the design of the LMA active fiber, the pulse energy is hard to scale to milli-joule level.…”