In what year was the inventor of the Abbe prism born?
Abbe prism In optics, an Abbe prism, named for its inventor, the German physicist Ernst Abbe, is a type of "constant deviation dispersive prism" similar to a Pellin–Broca prism.
Amici prism An Amici prism, named for the astronomer Giovanni Amici, is a type of compound dispersive prism used in spectrometers. The Amici prism consists of two triangular prisms in contact, with the first typically being made from a medium-dispersion crown glass, and the second a higher-dispersion flint glass. Light entering the first prism is refracted at the first air-glass interface, refracted again at the interface between the two prisms, and then exits the second prism at near-normal incidence. The prism angles and materials are chosen such that one wavelength (colour) of light, the "centre wavelength", exits the prism parallel to (but offset from) the entrance beam. The prism assembly is thus a "direct-vision prism", and is commonly used as such in hand-held spectroscopes. Other wavelengths are deflected at angles depending on the glass dispersion of the materials. Looking at a light source through the prism thus shows the optical spectrum of the source.