Energetic few-cycle pulse compression in gas-filled hollow core fiber with concentric phase mask

Zhao Yu^{1, 2}, Huang Zhi-Yuan^{1, 2}, Zhao Rui-Rui^{1, 2}, Wang Ding^{1, †}, Leng Yu-Xin^{1, ‡}

(a), (c), (e) Normalized spatial intensity distributions and (b), (d), and (e) radial intensity distributions of input pulses before propagating in HCF. Panes (a) and (b) show intensity profiles for LP Gaussian laser pulses, panels (c) and (d) show intensity profiles of incident focused LP Gaussian laser pulses after convex lens, and panels (e) and (f) show incident focal laser pulses after concentric phase mask and convex lens with duty cycle of 0.4.