UC Irvine

In this study, we present numerical evidence of a frozen mode in a periodic serpentine waveguide with broken longitudinal symmetry. This frozen mode is linked to a stationary inflection point (SIP) in the Bloch dispersion relation, where three Bloch eigenmodes coincide due to an exceptional point of order three. The frozen mode regime is characterized by a stationary group velocity and intensified field amplitude, making it highly appealing for diverse applications such as dispersion engineering, lasers, and delay lines. We have developed concise design equations that enable the realization of the frozen mode by adjusting a few key parameters. Our findings reveal distinct trends in group delay and quality factor with waveguide length specific to the frozen mode. Additionally, we explore the symmetry conditions necessary for the existence of exceptional points of degeneracy associated with the frozen mode.