Influence of finite spatial resolution on single- and double-pass femtosecond pulse shapers.

We investigate the influence of the finite spatial resolution of a typical 4f pulse-shaping setup in a single- and double-pass configuration on the shaped waveforms. Specifically, we calculate and measure the space-frequency distribution at the focal plane of a lens following the shaping setup and show that steep amplitude or phase jumps, as they appear with pixelated spatial light modulators, are affected by a finite spatial resolution.