SHG 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. 

Fig. 1. Spectral phase modulation in the femtosecond pulses is characterized (a) and compensated (b) using the MIIPS method. SHG-FROG traces for the pulses in panels (a) and (b) are shown in panels (c) and (d).

Fig. 3 The SHG FROG trace (a) and the amplitude profile (b) of the optimal laser field obtained after maximizing the CpMn(CO)2+ yield.

Fig. 1. Schematic of experimental setup. %J2 - 800 nm wave-plate SP 2-mm sapphire plate PI, 2 45° quartz prisms P3 69° quartz prism, the distance from P3 to the NOPA crystal is 80 cm CM1, 2 ultrabroadband chirped mirrors GR 300 lines/mm ruled diffraction grating (Jobin Yvon) SM spherical mirror, R=-400 mm BS1, 2 chromium-coated d=0.5 mm quartz beam splitters. SHG crystal 0.4-mm 0=29° BBO (EKSMA) NOPA crystal 1-mm 0=31.5° BBO (Casix) SHG FROG crystal 0=29° BBO wedge plate d=5- -20 pm (EKSMA). Spherical mirrors around NOPA crystal are R=-200 mm Thick arrows on the left indicate the data flow from the pulse diagnostic setup (SHG FROG) and the feedback to the flexible mirror.

Fig. 2. Overview of pulse shaping results, (a) and (b) depict measured SHG FROG traces before and after adaptive phase correction, respectively. Corresponding retrieved traces are displayed in (c) and (d). (e) Shows fundamental spectrum (shaded contour) measured at the crystal location in the FROG apparatus and the spectrum recovered by the FROG retrieval algorithm (open circles). Dash-dotted curve represents spectral phase prior to adaptive shaping, whereas dashed curve shows the optimized phase, (f) Initial (solid curve) and optimized (shaded contour) temporal intensity profiles. Dashed curve depicts temporal phase of the optimized pulse.

Fig. 6.79 An SHG FROG device (above) and the simpler version, GRENOUILLE (below) [787]...

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