T.A. Isaev The National Research Center "Kurchatov Institute", Konstantinov Petersburg Nuclear Physics Institute, Orlova Roshcha, Gatchina, Leningradskaya Region, 188300, Russian Federation
For a long time the methods of atomic laser cooling are applied for obtaining samples of cold and ultracold atomic gases including degenerate states
like Bose—Einstein condensates. Application of these methods for cooling of molecules has been considered non-feasible due to complex
structure of molecular levels resulting, in principle, in lack of closed cooling loops in transitions between electronic molecular levels.
Nevertheless, it has been recently established that direct laser cooling is feasible for a large class of molecules. These molecules include
not only simplest diatomic species,
but also polyatomic molecules. In the review we present some common principles on identification of the suitable molecules
and discuss the perspectives of further investigations with laser-coolable molecules.