Abstract
Coupled-resonator optical waveguides hold potential for slow-light propagation of optical pulses. The dispersion properties may adequately be analyzed within the framework of coupled-mode theory. We extend the standard coupled-mode theory for such structures to also include complex-valued parameters which allows us to analyze the dispersion properties also in presence of finite Q factors for the coupled resonator states. Near the band-edge the group velocity saturates at a finite value υg/c∝1/Q while in the band center, the group velocity is unaffected by a finite Q factor as compared to ideal resonators without any damping. However, the maximal group delay that can be envisioned is a balance between having a low group velocity while not jeopardizing the propagation length. We find that the maximal group delay remains roughly constant over the entire bandwidth, being given by the photon life time τp = Q/Ω of the individual resonators.
Highlights
The coupled-resonator optical waveguide (CROW) was first proposed and analyzed by Yariv et al [1]
To take full advantage of the CROW concept, the quality factor Q should be sufficiently high that the photon life time τp of an isolated resonator much exceeds the tunneling time τt in which case the group velocity will be of the order vg ∼ a/τt with a being the spacing of the resonators
We have derived an explicit relation for the dispersion relation of CROWs made from resonators with a finite
Summary
The coupled-resonator optical waveguide (CROW) was first proposed and analyzed by Yariv et al [1]. To take full advantage of the CROW concept, the quality factor Q should be sufficiently high that the photon life time τp of an isolated resonator much exceeds the tunneling time τt in which case the group velocity will be of the order vg ∼ a/τt with a being the spacing of the resonators. Broadening of van Hove singularities in photonic crystal waveguides limits the slow down near band edges [14] and for the CROWs we find a similar effect which can be studied explicitly within the framework of coupled mode theory. We discuss the maximal group delay that one may achieve with CROWs (see Section 4) and as an example we apply the coupled-mode formalism to a photonic crystal waveguide structure (see Section 5).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the European Optical Society-Rapid Publications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
