Ultrafast Science / 2022 / Article / Fig 4

Research Article

Factor 30 Pulse Compression by Hybrid Multipass Multiplate Spectral Broadening

Figure 4

(a) Broadened spectra after 32 roundtrips in a 385 mm long MPC detected with a response function corrected grating spectrometer. The spectra are offset by the output energy measured with an energy meter and corrected by the wedge W1 transmission. 0 J refers to the input spectrum. (b) Corresponding spectral broadening factors as a function of output pulse energy. The transform-limited pulse duration at full power is more than 30 times shorter than at the input. The MPC transmission is constantly about 80%. (c) Spectral side-bands, becoming detectable for more than 30 J output energy. These are excited by four-wave mixing as qualitatively predicted by simulations. The spectra are normalized to the maximum of the respective self-phase modulated part near 1030 nm. (d) Spectral broadening in dependence of pulses per burst. Despite the strongly changing beam parameters caused by transient thermal lenses in the main amplifier, the large broadening factor is preserved. (e) Spectrum stability measured over 17 hours with one recording per second.