Optical trapping efficiencies from n-phase cylindrical vector beams

We present the use of n - phase cylindrical vector beams in optical trapping. The vector beams are created via a Mach- Zehnder interferometer equipped with tunable phase plates, and the "n" prefix indicates the relative phase between the Hermite-Gaussian modes comprising the output beam. The optical trapping efficiency is measured via the Stokes drag force method for radial and azimuthal vector beams with n = 0 and π, giving a total of 4 unique input beams. Additionally, their trapping efficiencies are compared with that of a standard Gaussian input beam of equal input power. We find that the axial trapping efficiency can be optimized by increasing the amount of longitudinal (z) polarization at the focal plane of the trapping objective. Further, the lateral trapping efficiency is determined by the focal spot diameter, as expected, and can be similarly tuned by varying the relative phase between the vector beams' eigenmodes. The results suggest that cylindrical vector beams may be tuned such that both axial and lateral trapping efficiencies can be maximized.

[1]  Halina Rubinsztein-Dunlop,et al.  Forces in optical tweezers with radially and azimuthally polarized trapping beams. , 2008, Optics letters.

[2]  Qiwen Zhan,et al.  Radiation forces on a dielectric sphere produced by highly focused cylindrical vector beams , 2003 .

[3]  A. Ashkin.  Forces of a single-beam gradient laser trap on a dielectric sphere in the ray optics regime. , 1992, Methods in cell biology.

[4]  Miles J. Padgett,et al.  Axial and lateral trapping efficiency of Laguerre–Gaussian modes in inverted optical tweezers , 2001 .

[5]  P Guyot-Sionnest,et al.  Plasmon resonance-based optical trapping of single and multiple Au nanoparticles. , 2007, Optics express.

[6]  B. Hecht,et al.  Principles of nano-optics , 2006 .

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

[8]  Kishan Dholakia,et al.  Optical Tweezers With Increased Axial Trapping Efficiency , 1998 .

[9]  Alexander Rohrbach,et al.  Stiffness of optical traps: quantitative agreement between experiment and electromagnetic theory. , 2005, Physical review letters.

[10]  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.

[11]  Yasuhiro Takaya,et al.  Measurement of axial and transverse trapping stiffness of optical tweezers in air using a radially polarized beam. , 2009, Applied optics.

[12]  J. Chen,et al.  FDTD approach to optical forces of tightly focused vector beams on metal particles. , 2009, Optics express.

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