We propose a new class of systems holding PT-symmetry only locally; the potential fulfills: U(r-r0)=U*(-r+r0 ) in a small neighborhood of any point r0, whereas on a global scale the system is only Parity symmetric: U(r-r0)=U(-r+r0) for all r. We show that such systems lead to a strong field localization at r=0, arising from the merge of the two different symmetries. We explore these new potentials in one- and two- dimensional complex nanophotonic structures, combining gain/loss and index modulations, which we expect to have direct applications as turning broad aperture lasers into bright and narrow output beam sources.

Peer Reviewed