Numerical Modeling of Optical Parametric Chirped Pulse Amplification to Design a Petawatt Laser Front End

A numerical model of optical parametric chirped pulse amplification (OPCPA) was developed and used to investigate two designs for the front end of a proposed petawatt laser, which is a very high intensity laser. A petawatt laser is required for fast ignition, a new technique that has the potential to greatly benefit the study of Inertial Confinement Fusion (ICF) and is being investigated at various laboratories around the world. The first design, which is for a proof-of-principle experiment, was one which attempts to preserve the spectral characteristics of the input pulse in order to obtain a short temporal pulse width upon recompression. The second design, which is for the actual petawatt laser system, was one which modifies the spectral characteristics of the input pulse in a way that is desirable for injection into the glass amplifier chain. In both cases the number of crystal stages required and the approximate crystal lengths were determined using the model. The proof-of-principle design requires four crystals of BBO while the actual front end system design requires three longer BBO crystals. 1