Figure 4: Analysis of the integrator's temporal response.

The main plots represent both the experimental (black curve) and the theoretical (blue curve) time integrals (intensity waveforms) of all the optical input waveforms under analysis. The latter are reported in the corresponding insets (red curves). The measurement is performed for different cases: an ultrashort optical pulse directly generated by the laser source (a); in-phase pulses with a relative temporal delay of 40 ps (b); π-shifted pulses with a relative temporal delay of 40 ps (c); in-phase pulses with a relative temporal delay of 275 ps (d); π-shifted pulses with a relative temporal delay of 275 ps (e); a linearly chirped (quadratic phase) broadband optical pulse, with a field amplitude FWHM time duration of ∼1,340 ps (f). The impulse response (a, inset (A)) was obtained by using a fast (τ∼8 ps) amplified photo-detector. The dispersed pulse was calculated by assuming an ideal quadratic phase variation on the measured temporal amplitude pulse profile according to the linear dispersion value (∼2,000 ps nm⁻¹) of the fibre-dispersive element used in our experiments.