ABSTRACT
Ever since their invention by Rowland in 1883 [7.1], concave diffraction gratings have played an important role in spectroscopy. Compared with plane gratings they offer the important advantage of providing the focusing or imaging properties that otherwise have to be supplied by additional elements. This advantage enabled concave gratings to dominate the field of spectrometry for many years. When advances in photoelectronics made monochromator-based instruments more attractive, there was a natural shift to plane grating designs.
