Group Delay Control in Longitudinal Offset Coupled Resonator Optical   Waveguides
  We study the differential group delay that can be obtained in coupled micro-ring resonator waveguides with longitudinal offset couplers. Various devices based on this effect are proposed and analyzed using a finite-differences time-domain method and their potential applications are discussed. 
P. Chamorro-Posada and F.J. Fraile-Pel\'aez
physics.optics