Tight Focusing Properties of Azimuthally Polarized Lorentz Gaussian Beam
J. Environ. Nanotechnol., Volume 4, No 4 (2015) pp. 52-55
Abstract
The tight focusing properties of azimuthally polarized Lorentz Gauss beam is investigated theoretically by Vector Diffraction Theory. It is observed from the results that Non-Vortex Lorentz Gauss beam generated a sub wavelength focal hole under the tight focusing condition. It is also noted that FWHM of the focal hole andits focal depth suffers little change with the change in Lorential parameter. However when annular obstruction is introduced, the focal hole seems to get confined and improvement in the focal depth is observed. Focusing of Lorentz Gauss beam one optical vortex shows the formation of focal spot of sub wavelength size. It is also noted introduction of annular obstruction improved focal depth and reduced the spot size of the generated focal spot for the Lorential parameters considered.
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Reference
Bandres, M. A. and Gutiérrez, J. C., Vega, Cartesian beams, Opt. Lett., 32(23), 3459-3461(2007).
doi:10.1364/OL.32.003459
Casey, H. C., Pannish, M. B., Heterostructure lasers, Academic Press, New York, 1978.
Du, C., Zhao, Y. and Cai, Propagation of lorentz and Lorentz-Gauss beams through an apertured fractional fourier transform optical system, Opt. Lasers Eng., 49, 25-31 (2011).
doi:10.1016/j.optlaseng.2010.09.004
Dawei Zhang, Mei Ting, Xiumin Gao and Songlin Zhuang, Focusing of linearly polarized Lorentz-Gauss beam with one optical vortex, Optik, 124, 2969-2973(2012).
Dumke, W. P., Angular beam divergence in double-heterojunction lasers with very thin active regions, IEEE J. Quantum Electron., 11(7), 400-402(1975).
doi:10.1109/JQE.1975.1068627
Gawhary, O. E. and Severini, S., Lorentz beams and symmetry properties in paraxial optics, J. Opt. A, Pure Appl. Opt., 8, 409-414(2006).
doi:10.1088/1464-4258/8/5/007
Li, J. Y., Chen, S., Xu, Y., Wang, M., Zhou, Q., Zhao, Y., Xin, F. and Chen, Propagation properties of Lorentz beam in uniaxial crystals orthogonal to the optical axis, Opt. Laser Technol., 43 ,506-514(2011).
doi:10.1016/j.optlastec.2010.07.007
Naqwi, A. and Durst, F., Focusing of diode laser beams: A simple mathematical model, Appl. Opt., 29(12), 1780-1785(1990).
doi:10.1364/AO.29.001780
Richards, B. and Wolf, E., Electromagnetic diffraction in optical systems II. Structure of the image field in an aplanatic system, Proc. R. Soc. London, Ser. A, 253, 358-379(1959).
doi:10.1098/rspa.1959.0200
Saraswathi, R. C., Prabakaran, K., Rajesh, K. B. and Jaroszewicz, Z., Tight focusing properties of radially polarized Lorentz-Gaussian beam, Optik, 125, 5339-5342(2014).
doi:10.1016/j.ijleo.2014.06.058
Torre, A., Evans, W. A. B., Gawhary, O. El. and Severini, S., Relativistic Hermite polynomials and Lorentz beams, J. Opt. A: Pure Appl. Opt., 10, 1-16(2008).
Xiumin Gao, Dawei Zhang, Mei Ting, Fu Rui, Qiufang Zhan and Songlin Zhuang, Focus shaping of linearly polarized Lorentz beam with sine-azimuthal variation wavefront, Optik, 124, 2079- 2084(2013).
doi:10.1016/j.ijleo.2012.06.061
Youngworth, K. S. and Brown, T. G., Focusing of high numerical aperture cylindrical-vector beams, Opt. Express., 7, 77-87(2000).
doi.org/10.1364/OE.7.000077
Yu, H., Xiong, L. and Lü, B., Nonparaxial Lorentz and Lorentz-Gauss beams, Optik, 121, 1455-1461(2010).
doi:10.1016/j.ijleo.2009.02.005
Zhou, G., Fractional fourier transform of Lorentz beams, Chin. Phys. B, 18, 2779-2784(2009).
doi:10.1088/1674-1056/18/7/026