New designs for an efficient N x N passive integrated optical star coupler are proposed in this paper. New concepts, namely, grating degeneration and sandwich structures are presented. The new techniques and their combinations can significantly reduce the number of gratings required by the coupler and thus make it possible to build holographic N x N star couplers with recording materials of a moderate dynamic range.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics