Efficient and high-spatiotemporal-quality terawatt-class mid-infrared optical parametric amplifiers by spatially shaped pumping

We propose a method to efficiently generate terawatt (TW )-class mid -infrared (MIR) femtosecond laser pulses with high spatiotemporal quality through optical parametric chirped -pulse amplification (OPCPA). By transforming the pump -beam profile for the OPCPA from Gaussian to flat -top using a designed field mapping optics consisting of two aspherical lenses, we obtain a TW-class femtosecond laser pulse at 2 mu m with a conversion efficiency of over 36% according to our simulations. Furthermore, the spatiotemporal coupling effects are greatly suppressed in our method compared to an OPCPA system that is pumped by a widely employed Gaussian profile beam. Our work provides a simple and robust method for developing OPCPA systems with high efficiency and high pulse quality. (c) 2024 Optica Publishing Group