Optical properties of topological insulators and their applications for pulsed solid-state lasers

Topological insulators (TI) in two (2D) and three (3D) dimensions is now a focus theme in condensed-matter physics for their unique phases of quantum matter, which are relative closely to the quantum spin Hall effect originating from the spin-orbit interactions. Just like ordinary insulators, topological insulators have insulating bulk energy gaps separating the conduction and valence bands. But their edges or surfaces are gapless, leading to a particular conducting metallic state that is protected by time-reversal symmetry. In particular, the gapless surface states, where the Dirac electrons are linear dispersion, and the narrow bulk gaps offer the topological insulators promising ability for light absorption over a broad spectral range. In this talk, the optical properties of TI will be introduced. Meanwhile, the progress of TI-based solid state pulsed laser will be discussed as well.