Direct measurement of picosecond lifetimes

A generally applicable technique is introduced for the direct measurement of lifetimes on the picosecond time scale. Use is made of a new type of Kerr cell which is activated by laser pulses and which allows for the first time the display of weak incoherent light signals on the picosecond time scale. The 1/e decay times of the fluorescing levels of DDI and cryptocyanine are found to be 14 ± 3 and 22 ± 4 psec, respectively.