CHARACTERIZATION OF SHORT PULSES BY SELF-DIFFRACTION IN LIQUID-CRYSTALS

We present measurements of picosecond laser pulses performed by exploiting the ''self-diffraction'' effect in two kinds of liquid crystalline materials: nematic liquid crystals (NLC) and polymer dispersed liquid crystal (PDLC). Results are in good agreement with those obtained by standard second harmonic generation techniques. The method exhibits several advantages, and the use of PDLC samples, which enable low noise measurements, makes the ''self-diffraction'' technique competitive with the standard ones.