Novel Unified Criterion to Optimize Power Coupling at Optical Directional Couplers with Discontinuity Interface

불연속 경계면을 갖는 광 방향성 결합기의 최적 결합효율을 위한 새로운 통합기준

Novel unified criterion to optimize power coupling at optical directional couplers with discontinuous input/output interfaces is first defined and evaluated numerically. The numerical results reveal that maximum power transfer between guiding slabs without discontinuous interfaces is dominated by conventional phase-matching condition while the guiding structures with discontinuous interfaces has maximum power transfer at an equi-partition condition, which describes the power distribution condition between two rigorous modes propagating through optical couplers.