Abstract: A topological bulk laser includes a topological photonic crystal (32) having an energy band inversion between dipole mode and quadrupole mode near the center of Brillouin zone and a trivial photonic crystal (31) not having band inversion for splicing to each other. The reflection and confinement of an optical field occurs at the interface; and the interface encloses to form a closed contour, thereby forming a laser cavity with an effective cavity feedback for lasing at the interior of the interface. This band-inversion-induced reflection mechanism induces single-mode lasing with directional vertical emission. At room temperature, the topological bulk laser can achieve low threshold, narrow linewidth, and a high side-mode suppression ratio, reduce the fabrication difficulty and costs, and improve heat dissipation and electrical injection efficiency, hence improving lifetime and stability of devices.

Abstract: A method is disclosed of fabricating all-dielectric flat lens with low refractive index comprising: selecting dielectric substrate material and lens structure material; determining incident wavelength; calculating phase modulation corresponding to each pillar unit; periodically sampling circular area of dielectric substrate with radius to obtain plurality of sampling points; calculating phase modulation required at position of each sampling point; obtaining pillar corresponding to each sampling point; arranging different dielectric pillars with low refractive index and same thickness are arranged on dielectric substrate, thereby obtaining all dielectric flat lens with low refractive index.

Abstract: A method is disclosed of fabricating all-dielectric flat lens with low refractive index comprising: selecting dielectric substrate material and lens structure material; determining incident wavelength; calculating phase modulation corresponding to each pillar unit; periodically sampling circular area of dielectric substrate with radius to obtain plurality of sampling points; calculating phase modulation required at position each sampling point; obtaining pillar corresponding to each sampling point; arranging different dielectric pillars with low refractive index and same thickness are arranged on dielectric substrate, thereby obtaining all dielectric flat lens with low refractive index.