Characterization of laser pulses used in measurements of optical properties in laser materials

Diagnostic techniques for characterizing the short-duration 1064-nm laser pulses used for measuring thresholds for laser-induced damage, nonlinear refractive indices, and amplifier saturation fluences are reviewed. Each of these experiments requires determination of the absolute flux in W/sq cm, F(x, y, t), passing through a plane, or of the absolute integrated fluence in J/sq cm, J(x, y), deposited in a plane. To measure flux or fluence in a plane, the laser beam is divided to form several equivalent planes in diagnostic beams. In these equivalent planes, photographic plates or vidicons are used to record the spatial profile of the beam, J(x, y), calorimeters to measure the pulse energy, E, and either streak cameras or oscilloscope/diode combinations to measure the pulse waveform, F(x, y, t). Then by numerical analysis two integrals are solved to determine normalization factors.