Figure 12.6 — Counter-propagating optical traps Figure 12.6 — Counter-propagating optical traps. (a) Ashkin’s 1970 realisation of an optical trap. (b) Optical mirror trap.Figure (a) is reprinted figure from Ashkin, Phys. Rev. Lett. 24, 156–9. Copyright (1970) by the American Physical Society.Figure (b) is reproduced with permission from Thalhammer et al., J. Opt. 13, 044024. Copyright (2011) IOP Publishing. Reproduced by permission of IOP Publishing. All rights reserved.