Photonics Dictionary: F

A multiple-beam interferometer, usually consisting of two flat plates, with high reflective ability. The plates are set parallel to one another by spacers so that lightwaves may bounce back and forth...

A highly reflective mirror that is usually flat on one surface and curved on the other, and that has silver, gold or aluminum deposited on glass, providing about 99 percent reflection.

A fiber Bragg grating (FBG) is a type of optical filter that is inscribed or "written" into the core of an optical fiber. It consists of a periodic modulation of the refractive index along the length...

A fiber laser is a type of laser in which the active gain medium is an optical fiber doped with rare-earth ions such as erbium, ytterbium, or neodymium. Fiber lasers generate coherent light through...

For a Fabry-Perot interferometer or etalon, a value for the transmission bandwidth which can be calculated as the ratio of the free spectral range to the full width half maximum of the transmission...

A retroreflector that can focus a beam of light, with one planar reflective surface, one spherical and a third that is either planar or convex cylindrical.

1. A flaw in a blank caused by folding the blank's surface during its formation. 2. The change in the direction of a system's optical axis caused by a reflective component.

The frequency space between consecutive transmission peaks in the transmission spectrum of a Fabry-Perot interferometer or etalon. The free-spectral range is inversely proportional to the distance...

Freeform mirrors refer to reflective optical components that deviate from traditional symmetric or rotationally symmetric shapes, such as spheres or paraboloids. Unlike conventional mirrors, which...

Fresnel reflection refers to the reflection of light at the interface between two different media with different refractive indices. This phenomenon was named after the French engineer and physicist...

An optical reflector with the reflective coating applied to the front surface of the substrate. This eliminates the ghost image formed with second-surface mirrors.