Proximity effect from an Andreev perspective

The current understanding of the superconducting proximity effect is reviewed taking into account recent experimental and theoretical results obtained for mesoscopic normal metal-superconductor junctions as well as superconducting weak links. Although known for 40 years the phenomenon remained poorly understood. Current insights are the result of theoretical developments leading to the nonequilibrium quasiclassical theory, getting experimental access to proximity structures on a submicron scale as well as by combining it with the knowledge developed in the 80s on quantum transport in disordered and ballistic systems.