Abstract
The development of ultrafast science urgently requires reliable high energy few-cycle laser pulse sources. Via few-cycle laser-gas interaction to generate the isolated attosecond pulses (IAP) remains the most stable, reliable and widely employed approach. To generate the few-cycle laser, researchers have developed and utilized a variety of pulse broadening and compression methods, such as free propagation in bulk, multi-plate continuum (MTP), gas-filled hollow-core fiber (HCF), filamentation in gas, multi-pass cells (MPC) and so on. In this talk, I will report on the multi-pass cell type spectrum broadening technique, which is exploiting the multiple-reflection characteristics of a Herriott cell in air to obtain sufficient spectral broadening. In this work, by implementing two stages of our MPC, we have recorded the white light spectrum supporting less than 7 femtoseconds few cycle pulse generations. At first stage, we compress a 500 fs, 1.89mJ Yb laser (1030 nm) to 25 fs 1.78mJ, with compression factor 20 and 94% efficiency. Subsequently, a short-focal-length multi-pass cell (MPC) is utilized, which also enables spectral broadening in ambient air, spanning over one octave at a -25 dB level.
Anyone interested is welcome to attend.