Fabrication and laser performance of triple-clad Yb-doped aluminophosphosilicate fiber

•An Yb-doped triple-clad fiber with two silica-based cladding was fabricated.•Chelate precursor doping technique and simple overcladding process made the triple-clad fiber.•Ultra-thin substrate tube is instrumental to preventing P2O5 evaporation.•Two-stage deposition process is able to offset element evaporation.•The fiber presented 560 W laser output with optical-to-optical efficiency of 68.7%.