Abstract
An octave-spanning supercontinuum is the key to achieve isolated sub-femtosecond pulses. Recently our laboratory developed a new technique to generate ultrashort pulses that have an octave-spanning continuous spectrum using a set of multiple fused silica plates (MPContinuum). For such a broadband spectrum, the pulse width is sensitive to dispersion. Thus, characterization of the pulse with an octave-spanning supercontinuum is important. Here, we demonstrate using polarization-gating cross-correlation frequency-resolved optical gating (PG-XFROG) to characterize an octave-spanning visible spectrum. A PG-XFROG trace with octave-spanning spectrum is measured. From this trace and using our iterative phase-retrieval algorithm, we can retrieve the spectral phase and amplitude of the MPContinuum generated in our laboratory. The full characterization of the MPContinuum pulses helps us in theoretically analyzing the generation process, and allows precise compression of the octave-spanning supercontinuum pulses to the sub-femtosecond regime.