09:30 〜 09:45
▲ [16a-C301-3] Exceptional Line Formation and Flip-of-States in Degenerate Optical Microcavities
キーワード：Microcavity, Branch point, Mode converter
In the context of non-Hermitian systems flip-of-state phenomenon associated with an encircled second order exceptional point (EP) have attracted considerable attention. With an adiabatic variation of the chosen control parameters around an EP in parameter space, the corresponding coupled eigenvalues can be permuted in eigenvalue plane, exhibiting EP as a second order branch point. However, for an EP outside the closed loop, corresponding eigenvalues retain their initial positions. Such phenomenon exploiting continuous tuning of parameters via multiple EPs is yet to be explored. In this paper we propose a special line, coined as exceptional line that connects the successive EPs in parameter plane by virtue of the coupling parameters. Exploiting the interplay between the EPs on cascaded state-flipping mechanism along exceptional line we report the robustness of such phenomenon in presence of multiple EPs inside/outside the contour described by smooth /fluctuating variation of coupling parameters. Novel cavity performance based on such robust scheme may open up a new class of integrated photonic devices.