Spaser Based on Dark Quadrupolar Mode of a Single Metallic Nanodisk

On the Laser Generation in Two-Dimensional Materials with Pumping by Quasitrapped Modes

“…In the numerical simulation, we varied the imaginary part of the permittivity of MoTe 2 to values at which losses were completely compensated; i.e., the reflection coefficient of the signal field from the metastructure became 1. In this case, = Im and the threshold gain coefficient of the entire metastructure can be obtained using the expression [27,28] for the imaginary part of the refractive index. For the case under consideration in Fig.…”

Lasing Effect in Symmetrical van der Waals Heterostructured Metasurfaces Due to Lattice-Induced Multipole Coupling

“…Photoluminescence (radiation from the system) can be simulated for an optically pumped metasurface using the near-field excitation from MoTe 2 bilayer of each disk in the regime of varying the imaginary part of MoTe 2 effective relative permittivity ε eff (ω), see the section S5.2 in Supporting Information , where formulas for ε eff (ω) takes into account the change in the carrier density N according to eqs (1)–(2) under conditions of OQTM-resonator. Figure 2 b shows the comparison of numerically calculated photoluminescence spectra of metasurface in the threshold and above-threshold regimes for various values of pump intensity corresponding to the different values of parameter 68 , 69 that determines imaginary part of ε eff (ω). For the parameters presented in Table S1 , the effective relative permittivity of MoTe 2 for threshold conditions equals to ε eff (λ 0 ) = 19.3096 – i 0.4619, where we take into account the change of the real part of relative permittivity near the resonance, see the section S5.3 in Supporting Information .…”