Needles of longitudinally polarized light: guidelines for minimum spot size and tunable axial extent.

Optical beams exhibiting a long depth of focus and a minimum spot size can be obtained with the tight focusing of a narrow annulus of radially polarized light, leading to a needle of longitudinally polarized light. Such beams are of increasing interest for their applications, for example in optical data storage, particle acceleration, and biomedical imaging. Hence one needs to characterize the needles of longitudinally polarized light obtained with different focusing optics and incident beams. In this paper, we present analytical expressions for the electric field of such a nearly nondiffracting, subwavelength beam obtained with a parabolic mirror or an aplanatic lens. Based on these results, we give expressions of the transverse and longitudinal full widths at half maximum of the focal lines as a function of the width of the incident annular beam and we compare the performances of the two focusing systems. Then, we propose a practical solution to produce a needle of longitudinally polarized light with a tunable axial extent and a transverse width reaching the theoretical limit of 0.36λ.

[1]  Nir Davidson,et al.  High-numerical-aperture focusing of radially polarized doughnut beams with a parabolic mirror and a flat diffractive lens. , 2004, Optics letters.

[2]  Kathleen S. Youngworth,et al.  Focusing of high numerical aperture cylindrical-vector beams. , 2000, Optics express.

[3]  A. Meixner,et al.  A high numerical aperture parabolic mirror as imaging device for confocal microscopy. , 2001, Optics express.

[4]  Shunichi Sato,et al.  Sharper focal spot formed by higher-order radially polarized laser beams. , 2007, Journal of the Optical Society of America. A, Optics, image science, and vision.

[5]  P. M. Anbarasan,et al.  Tight focusing of double ring shaped radially polarized beam with high NA lens axicon , 2011 .

[6]  M Stalder,et al.  Linearly polarized light with axial symmetry generated by liquid-crystal polarization converters. , 1996, Optics letters.

[7]  Michel Piché,et al.  4π Focusing of TM(01) beams under nonparaxial conditions. , 2010, Optics express.

[8]  A. Meixner,et al.  Tighter focusing with a parabolic mirror. , 2008, Optics letters.

[9]  M. Piché,et al.  Focusing a TM(01) beam with a slightly tilted parabolic mirror. , 2011, Optics express.

[10]  Y. de Koninck,et al.  Enhanced resolution in two-photon imaging using a TM(01) laser beam at a dielectric interface. , 2009, Optics letters.

[11]  Charles Varin,et al.  Acceleration of electrons from rest to GeV energies by ultrashort transverse magnetic laser pulses in free space. , 2005, Physical review. E, Statistical, nonlinear, and soft matter physics.

[12]  Gerd Leuchs,et al.  Focusing light to a tighter spot , 2000 .

[13]  Wieslaw Krolikowski,et al.  Revealing local field structure of focused ultrashort pulses. , 2011, Physical review letters.

[14]  A. Meixner,et al.  Probing highly confined optical fields in the focal region of a high NA parabolic mirror with subwavelength spatial resolution , 2003, Journal of microscopy.

[15]  Shunichi Sato,et al.  Generation of radially polarized Ti:sapphire laser beam using a c-cut crystal. , 2008, Optics letters.

[16]  T G Brown,et al.  Longitudinal field modes probed by single molecules. , 2001, Physical review letters.

[17]  G Leuchs,et al.  Sharper focus for a radially polarized light beam. , 2003, Physical review letters.

[18]  Q. Zhan Trapping metallic Rayleigh particles with radial polarization. , 2004, Optics express.

[19]  John William Strutt,et al.  on the diffraction of object-glasses , 1872 .

[20]  M. Davidson,et al.  Rapid three-dimensional isotropic imaging of living cells using Bessel beam plane illumination , 2011, Nature Methods.

[21]  M Rioux,et al.  Ring pattern of a lens-axicon doublet illuminated by a Gaussian beam. , 1978, Applied optics.

[22]  E. Wolf,et al.  Electromagnetic diffraction in optical systems, II. Structure of the image field in an aplanatic system , 1959, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[23]  P. Varga,et al.  Focusing of electromagnetic waves by paraboloid mirrors. I. Theory. , 2000, Journal of the Optical Society of America. A, Optics, image science, and vision.

[24]  Colin J. R. Sheppard,et al.  Imaging by a high aperture optical system , 1993 .

[25]  Luping Shi,et al.  Creation of a needle of longitudinally polarized light in vacuum using binary optics , 2008 .

[26]  D Courjon,et al.  Smallest lithographic marks generated by optical focusing systems. , 2007, Optics letters.

[27]  I. Golub,et al.  Toward the subdiffraction focusing limit of optical superresolution. , 2007, Optics letters.

[28]  Y. de Koninck,et al.  Two-photon excitation fluorescence microscopy with a high depth of field using an axicon. , 2006, Applied optics.

[29]  Improved contrast radially polarized coherent anti-Stokes Raman scattering microscopy using annular aperture detection , 2009 .

[30]  T G Brown,et al.  Polarization-vortex-driven second-harmonic generation. , 2003, Optics letters.

[31]  Susumu Noda,et al.  Sub-wavelength focal spot with long depth of focus generated by radially polarized, narrow-width annular beam. , 2010, Optics express.

[32]  T. Grosjean,et al.  Smallest focal spots , 2007 .

[33]  Yaoju Zhang,et al.  Improving the recording ability of a near-field optical storage system by higher-order radially polarized beams. , 2009, Optics express.

[34]  R. Dorn,et al.  The focus of light – theoretical calculation and experimental tomographic reconstruction , 2001 .