Semiconductor saturable-absorber mirror–assisted Kerr-lens mode-locked Ti:sapphire laser producing pulses in the two-cycle regime

TLDR

The bandwidth enhancement was achieved by spectral shaping of the output coupling, suppression of dispersion oscillations in double‑chirped mirrors, and a novel broadband semiconductor saturable‑absorber mirror. The laser produced sub‑6‑fs pulses (4.8‑5.8 fs) at 100 MHz and 300 mW, with a spectrum spanning 950 nm to 630 nm, extending into the yellow beyond the Ti:sapphire gain bandwidth. Pulses of sub‑6‑fs duration were achieved at 100 MHz and 300 mW.

Abstract

Pulses of sub-6-fs duration have been obtained from a Kerr-lens mode-locked Ti:sapphire laser at a repetition rate of 100??MHz and an average power of 300??mW.?Fitting an ideal sech2 to the autocorrelation data yields a 4.8-fs pulse duration, whereas reconstruction of the pulse amplitude profile gives 5.8??fs. The pulse spectrum covers wavelengths from above 950??nm to below 630??nm, extending into the yellow beyond the gain bandwidth of Ti:sapphire. This improvement in bandwidth has been made possible by three key ingredients: carefully designed spectral shaping of the output coupling, better suppression of the dispersion oscillation of the double-chirped mirrors, and a novel broadband semiconductor saturable-absorber mirror.