Fig. 1. Schematic representations: (a) proposed optical-sensing modality, and (b) underlying canonical boundary-value problem.

Fig. 2. Values of relative wavenumbers q/k0 of DT waves guided by the interface of magnesium fluoride (nd=1.377) and the chosen titanium-oxide chiral STF infiltrated by a fluid of refractive index nℓ. In Figs. 2–4, the blue and red curves represent different DT waves.

Fig. 3. Values of the angle of incidence θincC in the prism-coupled configuration in relation to the refractive index nℓ of the fluid infiltrating the chiral STF, as predicted by the canonical boundary-value problem.

Fig. 4. Dynamic sensitivity ρ as a function of nℓ in the prism-coupled configuration computed from the predicted data presented in Fig. 3.

Fig. 5. Absorptances (a) As and (b) Ap plotted as functions of θinc for Np=LSTF/2Ω∈{4,5,6}, when nℓ=1.33, χv=15°, Ld=200  nm, and nd=1.377+10−4i. Downward arrows indicate the peaks that represent the excitation of DT waves.