Third Harmonic Generation for Two-Color Ionization Injection in Laser-Plasma Accelerators

Many applications of beams from laser plasma accelerators (LPAs) require high brightness electron beams enabled by low emittance. One proposal to achieve ultra-low emittance from an LPA is a two-color laser configuration, where a long wavelength laser, with large ponderomotive force, is used to excite a plasma wakefield, while another trailing short wavelength laser is used to ionize inner shell electrons, injecting them in the accelerating phase of the wake. Commonly used for laser plasma acceleration are Ti:Sapphire based systems. We present simulation and experimental results of third harmonic generation from 810 nm wavelength centered, high fluence, short pulses for two-color ionization injection on the petawatt laser at BELLA Center.