Photonics Dictionary: G

The optical power loss caused by a space between axially aligned fibers.

Property of a surface which, because of directional reflection, is responsible for the degree to which reflected highlights or the images of objects may be seen as superimposed on the surface.

A photometer for measuring gloss by comparing the specular reflectance to that from a perfect specular reflector.

A laser system consisting of a planar PN junction within a single crystal of gallium arsenide. The pair of parallel, semireflective end faces produces a Fabry-Perot resonant cavity, whereas the other...

Ink used for writing on glass, and also for blackening the edges of lenses to prevent reflection. In the latter case, the refractive index of the ink must closely match that of the glass.

A lamp in which the ionization of the inert gas contained in it produces a glow in the space close to the negative electrode.

In a microscope, the diaphragm located between the Bertrand lens and the eyepiece, which is closed during conoscopic viewing to restrict the interference figures to that of a crystal lying on the...

Gram-positive bacteria are a group of bacteria that have a thick cell wall composed primarily of a substance called peptidoglycan. This thick peptidoglycan layer retains a stain called crystal violet...

Graphene is a two-dimensional allotrope of carbon consisting of a single layer of carbon atoms arranged in a hexagonal lattice pattern. It is the basic building block of other carbon-based materials...

Machinery used to grind and finish a component, such as a lens or prism, to a desired precision. Usually such machines carry a cup-shaped or flat tool (lap) into close contact with the part. An...

A plate of glass in which a face has been frosted by grinding or etching. It diffuses light by scattering in directions close to the incoming beam, but the light falls off rapidly at larger angles...

In an optical waveguide, a mode whose field decays monotonically in the transverse direction everywhere external to the core and which does not lose power to radiation. Also called bound mode.