Tight focusing properties of phase modulated azimuthally polarized doughnut Gaussian beam

• Published in: Optical and quantum electronics 2016-11, Vol.48 (11), p.1-12, Article 507
• Main Authors: Sundaram, C. Mohana, Prabakaran, K., Rajesh, K. B., Udhayakumar, M., Anbarasan, P. M., Musthafa, A. Mohamed
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Computer Communication Networks; Diffraction theory; Divergence; Electrical Engineering; Gaussian beams (optics); Lasers; Light diffraction; Normal distribution; Optical Devices; Optical materials; Optical trapping; Optics; Photonics; Physics; Physics and Astronomy; Polarized light; X-rays
• ISSN: 0306-8919; 1572-817X
• DOI: 10.1007/s11082-016-0765-x

The intensity distribution in the focal region of a high NA lens for the incident azimuthally polarized doughnut Gaussian beam transmitted through a multi belt spiral phase hologram (MBSPH) is studied on the basis of the vector diffraction theory. Here we report a new method that generates a needle of transversely polarized light beam with sub diffraction beam size of 0.48λ that propagates without divergence over a long distance of about 49λ in free space and designed a dedicated MBSPH to generate multiple focal spot of transversely polarized. The authors also expect such a light needle of transversely polarized beam may find its application when using optical materials or instruments responsive to the transversal field only and to use in multiple optical trapping.