Abruptly Autofocusing Behavior of Circular Butterfly-Gaussian Beams

In this paper, we introduce a novel class of circular Butterfly-Gaussian beams (BGB) and further investigate the propagation behaviors in linear media both analytically and numerically. Our results show that circular BGB will exhibit abruptly autofocusing behavior even without the action of external potentials, similar to the circular Airy field and Pearcey field. Both analytical and numerical prediction demonstrates that the autofocusing distance is just equal to the case of circular Pearcey beam. Moreover, it is interesting to see that the rapid oscillation after the focal point is completely eliminated during the autofocusing process. We further disclose that such autofocusing behaviors can be effectively controlled through adjusting the distribution factor and the optical vortices. We hope that such circular BGB will be able to provide a new method in optical micromanipulation and optical trapping in the future.