Vectorial Structure of the Far-field of a Cylindrical Vector Laguerre-Gaussian Beam Diffracted at a Circular Aperture
G-Q. Zhou
Based on the stationary phase method combined with the angular spectrum representation, an analytical expression of the vectorial structure of the cylindrical vector Laguerre-Gaussian beam diffracted at a circular aperture has been derived in the far-field. Here the vectorial structure denotes that the diffracted cylindrical vector Laguerre-Gaussian beam is uniquely decomposed into the transverse electric (TE) and the transverse magnetic (TM) terms. The analytical formulae of the energy flux of the TE term, the TM term, and the diffracted cylindrical vector Laguerre-Gaussian beam are also presented in the far-field, respectively. The vectorial structures of the two cases of the diffracted cylindrical vector Laguerre-Gaussian beam are compared in the far-field. Under certain conditions, interesting phenomena will appear in the vectorial structures of the two cases of the diffracted cylindrical vector Laguerre-Gaussian beam in the far-field, which are illustrated as examples. This research reveals the farfield structural properties of the cylindrical vector Laguerre-Gaussian beam diffracted at a circular aperture. Also, this research is useful to the particle trapping, dark-field imaging, optical cage, and laser machining involving the diffracted cylindrical vector Laguerre-Gaussian beam.
Keywords: Laser beam, cylindrical vector Laguerre-Gaussian beam, vectorial structure, far-field, circular aperture