RESUMO
Optical parametric chirped-pulse amplification (OPCPA) operation with low gain by seeding with high-energy, clean pulses is shown to significantly improve the contrast to better than 10(-10) to 10(-11) in a high-intensity Ti:sapphire laser system that is based on chirped-pulse amplification. In addition to the high-contrast broadband, high-energy output from the final amplifier is achieved with a flat-topped spatial profile of filling factor near 77%. This is the result of pump beam spatial profile homogenization with diffractive optical elements. Final pulse energies exceed 30 J, indicating capability for reaching peak powers in excess of 500 TW.
Assuntos
Óxido de Alumínio , Lasers , Titânio , Fatores de TempoRESUMO
A high stability electron bunch is generated by laser wakefield acceleration with the help of a colliding laser pulse. The wakefield is generated by a laser pulse; the second laser pulse collides with the first pulse at 180 degrees and at 135 degrees realizing optical injection of an electron bunch. The electron bunch has high stability and high reproducibility compared with single pulse electron generation. In the case of 180 degrees collision, special measures have been taken to prevent damage. In the case of 135 degrees collision, since the second pulse is countercrossing, it cannot damage the laser system.