Photonics Dictionary: F

A means of determining a prism's index of refraction by placing the prism so that its emergent face is perpendicular to the incident beam. This arrangement permits the determination of the prism's...

In a birefringent material, the index of refraction varies with the direction of vibration of a lightwave. That direction having a low refractive index is the fast axis; at right angles to it is the...

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 optic preform is a cylindrical glass rod or tube used as the starting material for manufacturing optical fibers. It serves as the precursor from which optical fibers are drawn. The process of...

One of the two major types of optical glass, the other being crown glass. Flint glass is softer than crown glass, has a higher dispersion and usually a higher refractive index.

Optical glass that possesses a refractive index equal to or less than 1.5, and an Abbe number that ranges from 62 to about 85.

The optical form of the crystal fluorspar, calcium fluoride, that is utilized for its low optical dispersion, its low refractive index, and its transparency to infrared and ultraviolet radiation.

A special laser glass made primarily of fluoride compounds that exhibits extremely low refractive index and allows greater levels of energy to be generated as the laser beam passes through the...

Reflection losses incurred at input and output of optical elements because of the difference in refractive index between glass and the immersion medium.

A method for measuring the index profile of an optical fiber by measuring the reflectance as a function of position on the end face.