title: Coupled mode theory analysis of mode-splitting in coupled cavity system.
abstract: We analyze transmission characteristics of two coupled identical cavities, of either standing-wave (SW) or traveling-wave (TW) type, based on temporal coupled mode theory.Mode splitting is observed for both directly (cavity-cavity) and indirectly (cavity-waveguide-cavity) coupled cavity systems. The effects of direct and indirect couplings, if coexisting in one system, can offset each other such that no mode splitting occurs and the original single-cavity resonant frequency is retained. By tuning the configuration of the coupled cavity system, one can obtain different characteristics in transmission spectra, including splitting in transmission, zero transmission, Fano-type transmission, electromagnetically-induced-transparency (EIT)-like transmission, and electromagnetically-induced-absorption (EIA)-like transmission. It is also interesting to notice that a side-coupled SW cavity system performs similarly to an under-coupled TW cavity. The results are useful for the design of cavity-based devices for integration in nanophotonics.
authors.affiliation: Laboratory of Photonics and Microwave Engineering, School of Information and Communication Technology, Royal Institute of Technology (KTH), Electrum 229, 164 40 Kista, Sweden.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.forename: Yikai
authors.initials: Y
authors.lastname: Su
authors.forename: Min
authors.initials: M
authors.lastname: Yan
authors.forename: Min
authors.initials: M
authors.lastname: Qiu