P. Chessa et al., Phase measurements without interferometry: 2D transverse phase detection by numerical beam intensity analysis, LASER PART, 17(4), 1999, pp. 681-692
A whole family of laser-plasma interaction experiments is based on the phas
e analysis of the laser pulse after the propagation in a plasma. Typically,
this phase is obtained by means of interferometry. As pulsed interferometr
y is a much more difficult task than taking simple images of the beam, we d
eveloped a numerical code for extracting phase information from images. The
technique, based on the algorithm of Gerchberg-Saxton, showed to be very e
ffective in retrieving 2D phase distributions of simulated as well as real
beams. The convergence of the algorithm is fast (some minutes on a personal
computer). The electronic noise in real images is intrinsically discarded
by the algorithm.