Photonic nanojet generated by a spheroidal particle illuminated by a vector Bessel beam

The photonic nanojet (PNJ) produced by a vector Bessel beam irradiating a dielectric spheroidal particle is investigated using the Discrete Dipole Approximation. The influence of the beam center, beam order, beam polarization type, and half cone angle of the vector Bessel beam on the characteristics of PNJ is analyzed. Several characteristics of PNJ including maximum intensity, the focal length, the effective length, and full width at half maximum are considered. The results show that the characteristics of the PNJ can be controlled by changing the four parameters of the Bessel beam. We think it will help to enhance the application of Bessel beams in generating PNJ and provide new properties to generate PNJ.