Fig. 1. Schematic of 1D photonic crystals. (a) Multilayer dielectric structure; (b) grating structure; (c) nanobeam structure

Fig. 2. DBR laser structure diagrams and photoluminescence line diagrams of different perovskite materials. (a) (b) Relationship between the photoluminescence intensity and pump energy of the DBR/CsPbBr₃ QD/DBR structure laser photoluminescence intensity and pump energy of a DBR/CsPbBr₃ QD/DBR laser^[55]; (c) (d) DBR/MAPbBBr₃ SC-TF/DBR structure laser, photoluminescence intensity and pump energy diagram^[59]

Fig. 3. Perovskite DFB laser. (a) Schematic of DFB laser based on CsPbBrI₂ perovskite; (b) functional relationship of output peak strength, FWHM and pump energy density ^[65]; (c) SEM image of of MAPbBr₃ DFB laser (inset: high-resolution cross section, scale is 100 nm); (d) output intensity as a function of pump energy density^[66]

Fig. 4. Nanobeam structure. (a) Schematic of the SiN nanobeam;(b) schematic of the CsPbBr₃ perovskite nanocrystal coupled SiN nanobeam photonic crystal cavity; (c) fluorescence decay of perovskite nanocrystals under two different conditions ^[74]; (d) schematic of the CsPb (Br/I)₃ perovskite nanocrystals coupled SiN nanobeam photonic crystal cavity; (e) cavity emission shows a nonlinear increase of the output intensity, while background emission shows a linear dependence on the pump intensity^[27]

Fig. 5. (a) 2D photonic crystal structure diagram; (b) rectangular lattice air hole slab; (c) triangular lattice air hole slab

Fig. 6. Structure diagram and spectrum. (a) Schematic of the MAPbI₃ Photonic crystal band-edge laser structure; (b) cross-section of the device^[76]; (c) SEM image of the 2D Photonic crystal with dimensions of the triangular grating [inset (bottom): photograph of the sample under oblique while-light illumination. Inset (top): first Brillouin zone of the 2D photonic crystal with labelled points of high symmetry]; (d) lasing output characteristics along with the far field patterns slightly below and above threshold^[26]

Fig. 7. (a) 3D PhC structure diagram; (b) schematic of colloidal crystal structure; (c) MAPbBr₃ film is in the form of reverse opal, and the illustration is colloidal template; (d) spectra of inverted opal MAPbBr₃ films at different incident energy densities^[90]

Table 1. Thresholds and test conditions for photonics crystal laser with different materials