Frequency-resolved optical gating FROG

The MIIPS of compensated pulses is shown in Fig. lb. To corroborate phase information retrieved from MIIPS, phase characterization was also done using second harmonic generation frequency resolved optical gating (SHG-FROG) [7], SHG-FROG traces of the pulses before and after compensation are shown in Fig. lc and Id. The final pulse-shaping step involved the controlled phase modulation of transform-limited pulses. 

The drawback of the techniques discussed so far is their lack of phase measurements for the different spectral components within the pulse spectral profile. This can be overcome by frequency-resolved optical gating technique (FROG) [776]. 

Fig. 6.78 The schematic of single-shot polarization-gate (PG) cross-correlation frequency-resolved optical gating (XFROG) setup. The orange beam and red beam represent the known reference pulse and unknown pulse, respectively. The experimental apparatus is essentially a PG FROG setup with the known reference pulse replacing one of the replicas. The apparatus becomes a Blind PG FROG setup when the known reference is replaced by an unknown one [779]...

---