Abstract: A semiconductor laser element a first ring resonator. The first ring resonator includes a first semiconductor stack including a first n-side semiconductor layer, a first p-side semiconductor layer, and a first active layer located between the first n-side semiconductor layer and the first A-side semiconductor layer, wherein the first ring resonator comprises a diffraction grating. The semiconductor laser element further includes a second ring resonator optically coupled to the first ring resonator by evanescent field coupling. The second ring resonator includes a second semiconductor stack including a second n-side semiconductor layer, a second p-side semiconductor layer, and a second active layer located between the second n-side semiconductor layer and the second p-side semiconductor layer, wherein a peak wavelength of light emitted by the second ring resonator is the same as a peak wavelength of light emitted by the first ring resonator.

Abstract: A topological laser system is described. The laser system comprises an array of optical elements arranged in an array and coupled between them such that the array is configured for supporting one or more topological modes. The plurality of optical elements comprises optical elements carrying gain material configured for emitting optical radiation in response to pumping energy. The laser system further comprises a pumping unit configured to provide pumping of a group of the optical elements of the array within at least a portion of the spatial region corresponding with said topological mode; and at least one output port optically coupled to one or more of the optical elements associated with said topological mode. The at least one output ports is configured for extracting a portion of light intensity from said laser system.

Abstract: A topological laser system is described. The laser system comprises an array of optical elements arranged in an array and coupled between them such that the array is configured for supporting one or more topological modes. The plurality of optical elements comprises optical elements carrying gain material configured for emitting optical radiation in response to pumping energy. The laser system further comprises a pumping unit configured to provide pumping of a group of the optical elements of the array within at least a portion of the spatial region corresponding with said topological mode; and at least one output port optically coupled to one or more of the optical elements associated with said topological mode. The at least one output ports is configured for extracting a portion of light intensity from said laser system.

Abstract: An electron beam shaping unit for use in electron beam column and a method for designing thereof is presented. The electron beam shaping unit is configured for affecting electron beams of high density or strong electron-electron repulsion. These 5 beams can always be modeled with multi electron wave function. The electron beam shaping unit comprises a mask unit configured for affecting propagation of electrons therethrough to thereby form a propagating electron beam having, at far field, radial shape as determined by multi-electron non-linear function being an eigen function determined by a multi-electron Hartree-Fock Hamiltonian.

Abstract: An electron beam shaping unit for use in electron beam column and a method for designing thereof is presented. The electron beam shaping unit is configured for affecting electron beams of high density or strong electron-electron repulsion. These 5 beams can always be modeled with multi electron wave function. The electron beam shaping unit comprises a mask unit configured for affecting propagation of electrons therethrough to thereby form a propagating electron beam having, at far field, radial shape as determined by multi-electron non-linear function being an eigen function determined by a multi-electron Hartree-Fock Hamiltonian.