This article deal with phase diagnostics of femtosecond laser pulses and with its change to increase a nonlinear optical signal. We introduce a single shot technique of complex diagnostics SPIDER, which works on the base of interference in spectral region. Phase characteristics of investigated fs pulses incoming from oscillator was controlled by a prism pair. There was shown that phase characteristics changes of fs pulses leads to intensity changes of two photon fluorescence of coumarine C522 in ethanol.