![Fig. 8.14 — Trap steering](https://i0.wp.com/opticaltweezers.org/wp-content/uploads/2015/11/Fig8_14.png?fit=660%2C574)
The position of an optical trap can be changed within the sample (a) along the vertical z-direction by displacing one of the lenses in a telescopic arrangement and (b) in the horizontal xy-plane by conjugating the plane of a steerable mirror to the objective back aperture (BA). (c) It is also possible to construct a dual optical tweezers where a beam is split into two and recombined using two polarising beam splitters (PBS1 and PBS2) in order to create two independently steerable optical traps; the choice of polarising beam splitters is to avoid losing optical power.
Fig. 8.14 — Trap steering