Monochromatic lights have a low pressure sodium light source that emits monochromatic light in which rays have virtually the same wavelength. This light is a very effective way of viewing fringe ...

Optical flats are single precision flat surfaces. They are used as reference surfaces to compare flatness of a substrate where flatness is unknown. When a high quality optical flat is placed on top of ...

THE Thomson scattering of light by free electrons has not yet been observed in a laboratory plasma—the cross-section for the process is small and until recently no suitable source of light has been ...