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Toward an ultrafast double-pulse stretcher–compressor

The design of an ultrafast double-pulse stretcher–compressor, which can be utilized in applications like Raman chirped adiabatic passage experiments, is presented. Experimental PG FROG traces obtained for a single-pulse output of such a stretcher–compressor support the design. However, the FROG traces of a double-pulse output are not intuitive and not fully retrievable. Therefore, a code was developed to simulate these FROG traces and investigate their dependence on the delay between the two slices of the double-pulse. The results are presented here and can be employed as a diagnostic tool in different applications where ultrafast laser double-pulses are used. The simulations reveal that the FROG traces strongly depend on the delay between the two slices of the double-pulse when this delay is comparable to the pulse duration. The simulations also suggest that using a transform-limited single-pulse as the gate in the PG FROG instrument leads to simpler FROG traces.