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The effect of the temporal pulse shape of intense pulses on the momentumdistribution of $e^+e^-$ pairs is studied using the quantum kinetic equation.Two closely resembling temporal envelopes namely, Gaussian and Sauter, keepingall the other pulse parameters the same, are considered to this end. Contraryto the common perception which can be gauged from the interchangeable use ofthese temporal profiles, the longitudinal momentum spectrum of the pairscreated by the two pulses is found to differ significantly in all the temporalregimes. For the pulses having a few cycles of oscillations, the temporalprofile of the pulse is revealed in the oscillatory interference pattern ridingover the otherwise smooth longitudinal momentum spectrum at asymptotic times.The onset of the oscillation due to the quantum interference of reflectionamplitudes from the scattering potential due to the pulses having a temporalstructure of multiple barriers takes place for few-cycle oscillations for theGaussian pulse than that for the Sauter pulse. Furthermore, the oscillationamplitude for the same number of oscillations within the pulse duration islarger for the Gaussian pulse. The presence of the carrier-envelope phase andthe frequency chirping is found to magnify these differences. In the absence ofany appreciable interference effect for the pulses having less than fiveoscillations, the longitudinal momentum spectrum has a higher peak value forthe Sauter pulse at asymptotic times. On the hand, before the transient stageof evolution, the peak of the spectrum shows the opposite trend.

Imprint of temporal envelope of ultrashort laser pulses on longitudinal momentum spectrum of $e^+e^-$ pairs