Quartic-Phase Limited Grism-Based Ultrashort Pulse Shaper

By replacing the dispersive element in a zero-dispersion pulse shaper with a grism, we have constructed a quartic-phase limited pulse shaper. We demonstrate compensation of 4500 fs2 without the use of a dynamic element in the pulse shaping line, which is approximately the amount of dispersion induced by a typical multi-photon microscope. We also demonstrate that detuning the pulse shaper to compensate for quadratic phase induces negligible spatial chirp, thereby maintaining a high quality focal spot for a microscopy setup.