Observation of PT-symmetry breaking in complex optical potentials

Phys Rev Lett. 2009 Aug 28;103(9):093902. doi: 10.1103/PhysRevLett.103.093902. Epub 2009 Aug 27.


In 1998, Bender and Boettcher found that a wide class of Hamiltonians, even though non-Hermitian, can still exhibit entirely real spectra provided that they obey parity-time requirements or PT symmetry. Here we demonstrate experimentally passive PT-symmetry breaking within the realm of optics. This phase transition leads to a loss induced optical transparency in specially designed pseudo-Hermitian guiding potentials.