Determination of the intensity of two-photon-excited luminescence as a method for determination of the duration of picosecond laser pulses

A comparison of the integrated intensity of the luminescence excited as a result of two-photon absorption of picosecond and nanosecond pulses yielded the ratio of their durations. The method was applied to determine the duration of pulses emitted by a YAG:Nd³⁺ laser with passive mode locking.