13 May 2014 To construct a stable and tunable optical trap in the focal region of a high numerical aperture lens
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Abstract
Based on the diffraction theory, the focusing properties of a radially polarized quadratic Bessel–Gaussian beam (QBG) with on-axis radial phase variance wavefront are investigated theoretically in the focal region of a high numerical aperture (NA) objective lens. The phase wavefront C and pupil beam parameter μ of QBG are the functions of the radial coordinate. The detailed numerical calculation of the focusing property of a QBG beam is presented. The numerical calculation shows that the beam parameter μ and phase parameter C have greater effect on the total electric field intensity distribution. It is observed that under the condition of different μ , evolution principle of focal pattern differs very remarkably on increasing C . Also, some different focal shapes may appear, including rhombic shape, quadrangular shape, two-spherical crust focus shape, two-peak shape, one dark hollow focus, two dark hollow focuses pattern, and triangle dark hollow focus, which find wide optical applications such as optical trapping and nanopatterning.
© 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)
Gokulakrishnan Kandasamy, Suresh Ponnan, T. V. Sivasubramonia Pillai, Rajesh K. Balasundaram, "To construct a stable and tunable optical trap in the focal region of a high numerical aperture lens," Optical Engineering 53(5), 055106 (13 May 2014). https://doi.org/10.1117/1.OE.53.5.055106 . Submission:
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