  Phase modulation has come to be recognized as a fundamental paradigm for
optical device design in applications involving the spatiotemporal control of
optical wavefronts. Here, asymmetric resonant multilayer cavities based on the
inclusion of absorptive and lossless layers combined with the ideal conductive
metal allow for reflection and phase shift control in analogy with the
Fabry-Perot system, which in its basic configuration has zero reflection and
perfect transmission., the reflectivity of multilayers activated in a
prism-coupled geometry and composed of numerous stack layers but built in
different sequences has been examined. The layer's different arrangements,
resulting in open and closed asymmetric multilayers, display reflectance
spectra with distinct features as well as phase changes. For one of the studied
multilayer arrangements, two hybridized resonance modes form a strong coupling
with the exciton available from the red dye. As a result, energy-based
topological considerations identify a correlation between exciton/polariton
strong coupling, topological darkness, and phase tuning.
