EUROPHOTON 2022

Frequency-domain two-photon quantum interference between a thermal field and a heralded-state is studied theoretically and experimentally, revealing the dependency of visibility on the multiphoton components within the heralded-state.

We present an environmentally stable laser oscillator, mode-locked through nonlinear-polarisation evolution, that is entirely based on polarisation-maintaining fibres, except for the Yb-doped gain fibre. The laser is reliably operated at the fourth harmonic repetition rate, at 250 MHz, with output pulse energies of 1 nJ.

We report the compression of 1 ps duration, 112 muJ energy pulses from an YbYAG amplifier to 11 fs and the generation of an octave-spanning spectrum by two hybrid multi-pass multi-plate spectral broadening stages. Both, the compression factor and the output pulse duration set new records for bulk multi-pass cells.

We demonstrate nonlinear spectral broadening of 2.1-mJ, 670-fs pulses at 210 W of average power in a focus-free compact 61.5 cm distance, convex-concave MPC in ambient air. We show pulse broadening from 21 nm to 24.5 nm, and we demonstrate compressibility down to 134 fs with excellent spectral homogeneity.

We report on conical third harmonic generation that accompanies supercontinuum generation in fused silica using broadly tunable femtosecond pulses. Third harmonic radiation carries a broadband, octave-spanning spectrum, with propagation angles of individual spectral components precisely following the entire phase matching curve, as attested by the measurements of angle-resolved spectra.

We present a 108-fs Kerr-lens-modelocked, diode-pumped 1-GHz Tisapphire laser. Self-starting operation producing 103 mW was obtained for 1-Watt pumping with a single 520-nm laser diode. From 1 Hz1 MHz the relative intensity noise was 0.01 and the repetition rate was externally referenced with a phase error of 1.7 mrad.