  Topological photonics has recently been proved a robust framework for
manipulating light. Active topological photonic systems, in particular, enable
richer fundamental physics by employing nonlinear light-matter interactions,
thereby opening a new landscape for applications such as topological lasing.
Here we report an all-dielectric topological insulator laser scheme based on
semiconductor cavities formed by topologically distinct Kagome photonic
crystals. The proposed planar semiconductor Kagome lattice allows broadband
edge states below the light line due to photonic valley hall effect in
telecommunication region, which provides a new route to retrieve nontrivial
photonic topology and to develop integrated topological systems for robust
light generation and transport.
