Spatial control and diagnostics of femtosecond pulses with programmable microoptics

Spatial light modulators based on liquid-crystal-on-silicon micro-displays were investigated with respect to their capability to flexibly shape complex wavefields from femtosecond pulses. Experiments were performed with a Ti:sapphire laser oscillator emitting linearly polarized radiation at pulse durations in 10 fs range. It is shown that the transfer characteristics well enable for an undistorted adaptive shaping of microoptical phase profiles which are linearly dependent on the gray values at such ultrashort pulses. In particular, beam arrays consisting of individually programmable nondiffracting Bessel-like beams, needle beams and beam slices of high aspect ratios were generated. By composing complex patterns of nondiffracting subbeams, image information was propagated nearly undistorted over certain distances ("flying images"). Cross-talk was minimized by diffractive background management. Further applications like adaptive wavefront sensing, advanced autocorrelation as well as statistical encoding are discussed.