Optically addressed liquid crystal light valves and their applications

The beams delivered by high energy laser chains suffer from spatial and tem poral aberrations which degrade the performances of the source, These aberr ations araise from thermal lensing and group delay dispersion effects which reduce the available peak power density when focusing the beam on a target . To increase the laser brightness to a value close to the diffraction limi t in the space and time domains we propose to use a liquid crystal spatial phase modulator. It consists of an optically addressed light valve which pe rmits to control the phase of a wavefront and the phase of each spectral co mponent of an ultrashort femtoseconde pulse. We present the technology and the characteristics of the device and demonstrate the following application s: wavefront correction. compensation of group delay dispersion and dynamic holography with gain.