Ultra-high intensity temporally oscillatory optical Kerr effect in Carbon Disulfide arising from electronic and molecular distortions

Abstract

Temporal oscillatory structure of Kerr induced birefringence is revealed in Carbon Disulfide (CS2) using an intense femtosecond optical pump pulse. The optical Kerr effect using temporal gates were experimentally investigated using a 300 fs 600 nm probe and a 1200 nm pump pulses. Several input pump powers and focusing lenses were used to show how the oscillator nature of Kerr Gating scales with input pump intensity. Temporal curves were also simulated using the two primary Kerr (n2) mechanisms: the ultrafast electron cloud (n2(e)) and the slower molecular motion (n2(m)) distortions. Results reveal high level oscillatory structure in CS2 that had been previously unreported and show the influence of pulse duration on relaxation processes. The discrepancies between high intensity gates and corresponding simulated curves display the impactful role of plasma generation in Kerr processes at extreme intensities.