Fig. 1. (a) Sketch of the Kretschmann–Raether configuration to investigate guided modes in a stack consisting of encapsulated perovskite thin film of thickness h on a silver substrate. (b), (c), (d) Results of transfer matrix calculations corresponding to the case h=30  nm: (b), (c) angle-resolved reflectivity spectra in TM-polarized light of (b) passive and (c) active structures; (d) field distribution of the SPP mode shown in (b). (e)–(k) Results of transfer matrix calculations corresponding to the case h=150  nm: (e)–(h) angle-resolved reflectivity spectra in (e), (g) TM and (f), (h) TE-polarized light of (e), (f) passive and (g), (h) active structures; (i)–(k) field distribution of modes shown in (e) and (f).

Fig. 2. (a) Design of the perovskite metasurface. (b), (d), (e), (f) Folded dispersion of different guided modes extracted from Figs. 1(b), 1(e), 1(f) with period a=300  nm. (c), (g), (h) Angle-resolved reflectivity spectra obtained from RCWA calculations for (c) h=30  nm and (g), (h) h=150  nm. All of these calculations are carried out with a=300  nm, η=0.3, and f=0.9.

Fig. 3. (a)–(c) Angle-resolved reflectivity spectra obtained from RCWA calculations for the passive metasurface of (a) f=0.16, (b) f=0.29, and (c) f=0.57. All of these calculations are carried out with a=300  nm, η=1, and h=30  nm. (d), (e) Field distribution of the dark and bright modes. (f) Ratio of radiative quality factors as a function of kx for different values of the filling fraction f. (g), (h) Spectral position and quality factor of the dark and bright modes at kx=0 as functions of the filling fraction f.

Fig. 4. (a)–(c) Angle-resolved reflectivity spectra obtained from RCWA calculations for the passive metasurface of (a) f=0.4 and a=270  nm, (b) f=0.51 and a=267  nm, (c) f=0.7 and a=261  nm. All of these calculations are carried out with η=0.3 and h=150  nm. (d), (e) Field distribution of the dark and bright modes. (f) Quality factor of the bright and dark modes in (c) as a function of kx. (e), (f) Spectral position and quality factor of the dark and bright modes at kx=kEP=0.177  μm−1 as functions of the filling fraction f. In these calculations, the period a is fixed at 265 nm. (i) Dip amplitude of the reflectivity resonance as a function of the spectral detuning to EP.

Fig. 5. (a)–(c) Angle-resolved reflectivity spectra obtained from RCWA calculations for the active metasurface of (a) f=0.4 and a=270  nm, (b) f=0.51 and a=267  nm, (c) f=0.7 and a=261  nm. All of these calculations are carried out with η=0.3 and h=150  nm. (d) Quality factor of the dark and bright polaritons in (c) as a function of kx. (g), (h) Spectral position and quality factor of the dark and bright polaritons at kx=kEP=0.13  μm−1 as functions of the filling fraction f. In these calculations, the period a is fixed at 265 nm.