Ultrafast vortex arrays generated from a mode-locked oscillator with dispersion management.

Herein, we demonstrate the generation of optical vortex arrays pulses using a Sagnac common-path interferometric vortex generator. Hermite-Gaussian (HG) modes with different orders are initially obtained from a SESAM mode-locked laser in the positive dispersion regime. Then, in the interferometric vortex generator, by controlling the phase difference and sheering displacement between two HG modes, optical vortex pulses with different numbers of phase singularities are generated through superposition. The generated HG mode has a pulse width of 2 ps and maximum energy of 0.75 nJ. One-dimensional vortex arrays and triangular vortex arrays are also generated, which are formed by HG and HG modes, respectively. This work has potential applications in the massive manipulation of microparticles, optical communication, and so on.