Mirror-dispersion-controlled OPA: a compact tool for sub-10-fs spectroscopy in the visible

We report on a sub-10-fs optical parametric amplifier in the visible, using noncollinear phase matching in B-barium berate, with a pulse compressor ma de exclusively of chirped dielectric mirrors. We employ mirrors of novel de sign, providing negative group delay dispersion for bandwidths of over 200 THz, up to the blue-green spectral region. The resulting setup, compact, ea sy to operate and reliable, is an ideal tool for ultrafast spectroscopy wit h extremely high time resolution. We use these pulses to observe in the tim e domain coherent oscillations in organic molecules with period as short as 16 fs.