Fig. 1. (a) 3D schematic diagram of the proposed MMPA and the incident light polarization configuration. The thicknesses of GST square resonators, silica spacer, and GST planar cavity are h=60  nm, t=30  nm, and T=180  nm, respectively. The lattice period in both x and y directions is p=300  nm, and the edge of the square resonator is w=160  nm. (b) Top view of the proposed MMPA showing the structural parameters. (c) 3D schematic diagram of the planar control device as a comparison, where the thicknesses T′ of GST is tunable to guarantee its volume equally to that of the MMPA. (d) Real n (solid line, black) and imaginary k (sample line, red) parts of the refractive index for the amorphous phase of GST.

Fig. 2. 3D FDTD simulation of spectra of (a) reflectance and (b) absorbance for the proposed MMPA, the device with only GST planar cavity, the device with only GST square resonators, and the planar control device with the amorphous GST under the illumination of normal incidence light, respectively.

Fig. 3. (a–c) Normalized electric field distributions and the (d–f) heat power volume density Qd of the absorption peaks at λ1−λ3 for the proposed MMPA with amorphous phase of GST at normal incidence, respectively. The Qd is in unit of W/m3.

Fig. 4. Contour plot of the absorption spectrum dependence on the (a) lattice period p, the (b) square dimension w, and the (c) thicknesses T of GST planar cavity, respectively. Herein, the other structural parameters are the same as those of Fig. 1(a). The absorption evolution versus the thicknesses of GST planar cavity for the control device with only GST planar cavity also is depicted in panel (d) as a comparison.

Fig. 5. (a) 3D-FEM simulation of heat power shining on the MMPA and the planar control device with amorphous GST located at the beam center, respectively. (b) Temperatures of GST square array in the MMPA and the GST cavity in the MMPA and the GST layer in the planar control device during one pulse. The cross section view of one unit cell of (c) MMPA and the (d) planar control device, where the color image indicates the temperature distribution, and the arrows indicate the heat flux at 0.56 ns.

Fig. 6. (a) Real (solid line, black) and imaginary (symbol line, red) parts of the refractive index for crystalline GST. (b) 3D FDTD simulation of spectra of reflectance and absorbance for the proposed MMPA with crystalline GST at normal incidence. The absorption response of the proposed MMPA with amorphous GST also is given for comparison. (c)–(d) Normalized electric field distributions at the absorption peaks for the proposed MMPA with crystalline GST at normal incidence, respectively.