Focusing petawatt-level laser beams to a variety of spot sizes for different applications is expensive in cost, labor and space. In this talk, we present a plasma lens, similar to an adjustable eyepiece in a telescope, to flexibly resize the laser beam by utilizing the laser self-focusing effect. Using a fixed conventional focusing system to focus the laser a short distance in front of the plasma, one can adjust the effective laser beam waist within a certain range, as if a variety of focusing systems were used. Such a setup is a powerful tool for laser wakefield accelerator experiments in state-of-art petawatt laser projects and allows for scanning focal spot parameters.
|Working group||Laser-driven electron acceleration|