Abstract: A system for the measurement of high bandwidth peak power pulses from laser sources. A laser pulse from a laser is directed onto the surface of a diffuser that replicates the pulse. A linear array of fiber optics of varying fiber length transmits the replicated pulses to a detector. The detector produces n pulses having a pulse width .lambda., each separated in time by a given time delay .DELTA.t which is directly proportioned to the length of each fiber. The output of the detector is fed to a digitizing oscilloscope to produce of digitized average pulse phase output.