Experimental Dataset for Efficient Pulse Compression and Frequency Down-Conversion Driven by Circularly Polarized Pulses in an Air-Filled Multi-Pass Cell

It records the spectral evolution, temporal compression characteristics, frequency down-conversion efficiency, and output beam quality of a driving laser with a central wavelength of 1030 nm and a pulse duration of 800 fs, under varying input pulse energies (up to 688 μJ) and polarization states (linear versus circular).

The dataset includes broadened spectra at different input energies, comparison of Raman redshift enhancement and anti-Stokes suppression induced by circular polarization, transform-limited compressed pulse duration (as short as 35 fs), tunable central wavelength range of filtered down-converted pulses (1040–1100 nm), conversion efficiency at 1090 nm (18%), temporal autocorrelation traces of output pulses, beam profile (Gaussian fit), and long-term energy stability (0.31% RMS over 100 minutes).