title: Generation of a strong uniform transversely polarized nondiffracting beam using a high-numerical-aperture lens axicon with a binary phase mask.
abstract: We present a theoretical approach to generate a nondiffracting beam with extended depth of focus (DOF) and a smaller focal spot along the optical axis, by tight focusing of an azimuthally polarized beam with a circular symmetrical binary phase mask and an interference effect over a high-numerical-aperture (NA) lens axicon system. We find a general azimuthal diffraction integral for the circularly symmetric binary phase mask and examine it in two special cases: a high-NA lens and a high-NA lens axicon. The azimuthally polarized beam remains well behaved in both cases. We verify that the longitudinal component generated by azimuthally polarized illumination produces the narrowest spot size for a wide range of geometries. Finally, we discuss the effects of tight focusing on a dielectric interface and provide some ideas for circumventing the effects of the binary phase mask interface and even utilize them for spot size reduction.
authors: Department of Electronics and Communication Engineering, National College of Engineering, Tirunelveli, Tamilnadu, India.
authors: P
authors: P
authors: Suresh
authors: C
authors: C
authors: Mariyal
authors: K B
authors: KB
authors: Rajesh
authors: T V S
authors: TV
authors: Pillai
authors: Z
authors: Z
authors: Jaroszewicz