Jinc-trap resonator

A Jinc-trap resonator has a Fourier transform resonator structure with a Jinc-trap spatial filter disposed in one of two opposite end transform planes. A near Jinc-like mode is effectively trapped at the one plane where the filter is located, while a corresponding transform mode that is nearly constant in amplitude and flat in phase is located at the opposite transform plane. The Jinc-trap spatial filter is composed of a first series of concentric absorption bands and a second series of concentric reflecting bands which alternate in position with the absorption bands.