  Rabi-like splitting and self-referenced refractive index sensing in hybrid
plasmonic-1D photonic crystal structures have been theoretically demonstrated.
The coupling between Tamm plasmon and cavity photon modes are tuned by
incorporating a low refractive index spacer layer adjacent to the metallic
layer to form their hybrid modes. Anticrossing of the modes observed at
different values of spacer layer thickness validates the strong coupling
between the two modes and causes Rabi-like splitting with different splitting
energy. Rabi-like splitting energy decreases with increasing number of periods
(N) and refractive index contrast ({\eta}) of two dielectric materials used to
make the 1D photonic crystals, and the observed variation is explained by an
analytical model. Angular and polarization dependency of the hybrid modes shows
that the polarization splitting of the lower hybrid mode is much stronger than
that of the upper hybrid mode. On further investigation, it is seen that one of
the hybrid modes remains unchanged while other mode undergoes significant
change with varying the cavity medium. This nature of the hybrid modes has been
utilized for designing self-referenced refractive index sensors for sensing
different analytes. For {\eta}=1.333 and N=10 in a hybrid structure, the
sensitivity increases from 51 nm/RIU to 201 nm/RIU with increasing cavity
thickness from 170 nm to 892 nm. For the fixed cavity thickness of 892 nm, the
sensitivity increases from 201 nm/RIU to 259 nm/RIU by increasing {\eta} from
1.333 to 1.605. The sensing parameters such as detection accuracy, quality
factor, and figure of merit for two different hybrid structures ([{\eta}=1.333,
N=10] and [{\eta}=1.605, N=6]) have been evaluated and compared. The value of
resonant reflectivity of one of the hybrid modes changes considerably with
varying analyte medium which can be used for refractive index sensing.
