Laser beam alignment for a petawatt picosecond diagnostic system in SG-II laser facility

Abstract

To satisfy the beam pointing and centering requirements of a sophisticated sampling beam path for petawatt picosecond diagnostic systems, a laser-beam alignment system is applied to this diagnostic platform. A mathematical model of a 4D linear matrix is applied to achieve rapid and accurate beam alignment. This alignment system can also switch quickly between two channels sampling beams without disturbing the beam’s pointing and centering. Experimental results indicate that the near-field centering accuracy is 0.3 mm and the far-field pointing accuracy is 0.16 mrad. With this alignment system, the picosecond diagnostic system can realize stable and reliable pulse width diagnostic between 1 and 10 ps, and obtains high dynamic range signal-to-noise ratio diagnostic results.