A dichroic material is either one which causes visible light to be split up into distinct beams of different wavelengths (colors), or one in which light rays having different polarizations are absorbed by different amounts.
SPHERICAL VS. ASPHERIC LENSES
HOW THEY’RE USED IN IMAGING APPLICATIONS
Optical Lenses are often categorized by their shape. Two common surface shapes are spherical and aspherical. Each offers unique characteristics that make it suitable for different use cases.