Abstract

We show that when an image bearing optical beam acquires a Berry phase during its propagation in a nonplanar optical system, its image is rotated by an angle identical to this phase in magnitude, but with an opposite sign, about one, well-defined, axis. Therefore, a measurement of the topological Berry phase of a given optical system can be performed by a direct measurement of the angle of rotation of its image about its optical axis. We show that since our method of measuring the Berry phase does not involve any coherent effects, it may be implemented with coherent as well as incoherent illumination. We demonstrate these arguments experimentally by measuring the Berry phase of a nonplanar optical system, using an incandescent light bulb, and compare it to conventional polarization based methods.

© 1992 Optical Society of America