Axial optical trapping (high NA, high np) — Geometrical Optics

Axial optical trapping: NA=1.30 nm=1.33 np=1.50.

Agnese Callegari, Mite Mijalkov, A. Burak Gököz, and Giovanni Volpe, “Computational toolbox for optical tweezers in geometrical optics,” J. Opt. Soc. Am. B 32, B11-B19 (2015).
http://dx.doi.org/10.1364/JOSAB.32.000B11