40th anniversary of Applied Physics B (Jacob I. Mackenzie)

In 2021 we celebrate the 40th Anniversary of the demarcation of the Springer Verlag journal Applied Physics into its two branches Applied Physics A: Solids and Surfaces and Applied Physics B: Photophysics and Laser Chemistry. The latter transforming into Applied Physics B: Lasers and Optics some 13 years later. To celebrate this occasion, we invited our top-cited and downloaded authors to contribute to a collection of review/tutorial papers, capturing their evolution over the intervening years as they ripened into new foundations for further progress in laser physics.