Realisation of a liquid crystal based prototype for duration measurement of picosecond pulses

Using self-diffraction technique, a prototype has been ideated and experimentally assembled for the measurement of the duration of laser pulses in the range of picoseconds. The innovative technique used is based on the presence of a dynamic diffraction grating written by the pulse on a film of liquid crystalline composite material under suitable geometrical conditions. The pulse to be measured undergoes a "self-diffraction" effect whose efficiency is related to the pulse duration. A software has been implemented both for the calculation of the pulse duration from the elaboration of experimental data and for the control of mechanical micrometric components.