Refractive–diffractive generation of ultrashort Airy–Bessel wave packets with orbital angular momentum: a comprehensive analysis

Bessel beams belong to the class of “non-diffracting” beams, which means that the field distribution near the optical axis does not broaden as the field propagates. Higher order Bessel beams have helical wavefronts and carry an orbital angular momentum. Such non-diffracting “vortex beams” play an important role in physics and engineering. Orbital angular momentum using ultrashort wave packets has been demonstrated in recent years. However, because of spatiotemporal dispersive coupling, spatial beam shaping affects the temporal properties of the pulse. To overcome this, dispersion compensation techniques may be applied, for example, by the combination of refraction and diffraction. Here, we present a comprehensive analysis of the generation of ultrashort Airy–Bessel wave packets taking into account third-order effects, in particular. Thus, one can explore the limits of this technique. It is shown that, for pulses with a duration of less than 10 fs, third-order dispersion has a significant impact on the pulse shape: a Gaussian profile (in time) is transformed into a temporal Airy profile. Our analysis also reveals that terms of higher order, i.e., fourth- and fifth-order dispersion, etc., are less significant.