In applications involving lasers with high peak intensities, such as optical amplification or pulse delivery through an optical fiber, self-phase modulation is an unwanted phenomenon which affects the spectrum, phase, and temporal profile of laser pulses. Here we report on the use of binary phase shaping for mitigation of self-phase modulation. We provide theoretical simulation and estimated efficiency of the mitigation supported by experimental results using both chirped and binary phase shaped pulses.
Measuring the speed and direction of vortices is of great importance in fluid dynamics. We report on the use of a CW
laser beam with a superposition of Laguerre-Gaussian (LG) modes generated by a phase mask imprinted on a two-dimensional
spatial light modulator. The shaped beam is then guided and scattered of a sample which is rotated; the
rotational frequency is extracted from spectral analysis of the scattered light. This method allows for virtually real-time
determination of vorticity characterization in a fluid.
The transition of femtosecond lasers from the laboratory to commercial applications requires real-time automated pulse compression, ensuring optimum performance without assistance. Single-shot phase measurements together with closed-loop optimization based on real-time multiphoton intrapulse interference phase scan are demonstrated. On-the-fly correction of amplitude, as well as second- and third-order phase distortions based on the real-time measurements, is accomplished by a pulse shaper.