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Engineerable femtosecond pulse shaping using SHG with aperiodic QPM structures

Manipulation of the temporal shape of ultrashort optical pulses is important for many applications. Conventional pulse-shaping techniques filter optical frequency components spatially dispersed with a grating apparatus. Here we demonstrate an alternative approach, which uses second-harmonic generation (SHG) with aperiodic quasi-phase-matching (QPM) structures. This technique allows generation of almost arbitrary second-harmonic waveforms using compact monolithic devices.