Nonparaxial propagation and the radiation forces of the chirped annular Bessel Gaussian beams

We propose a new class of abruptly autofocusing beams, the chirped annular Bessel Gaussian beams (CABGBs), which are based on the radial Bessel profile. By using the Rayleigh–Sommerfeld diffraction formula, the nonparaxial propagation of the CABGBs is investigated. We find that the initial chirp with negative value tends to intensify the abruptly autofocusing property by shortening the focal length, shrinking the focal spot size, and increasing the peak intensity contrast. The optical trapping effect of the CABGBs acting on a Rayleigh particle is analyzed, and we find that the particle can be stably trapped in three dimensions if the parameters of the CABGBs are appropriate. If the absolute value of the negative chirp increases, the trapping position is shifted toward the input plane, and both the longitudinal and transverse trapping forces rise. A higher magnitude of the radiation forces can be reached if the incident power increases.