Photonics Dictionary: I

A type of refractometer designed to measure the refractive indices of liquids. A section of the instrument is immersed into the sample being measured.

The ratio of the velocity of light in a vacuum to the velocity of light in a refractive material for a given wavelength.

A radiation detector with its active medium mounted within a lens that focuses the radiation signal. The improvement in detector performance is a function of the indices of refraction of the lens...

Term synonymous with refractive index liquid, but related more to tank or chamber immersion of crystals, fibers, lenses, photoelastic models, etc.

In the context of optical materials, the term "impurity level" refers to the presence of foreign atoms or molecules within the material that deviate from its regular or intrinsic composition. These...

The decrease in the refractive index at the center of a fiber's core, caused by certain fabrication techniques. Also called profile dip.

In an optical waveguide, the refractive index as a function of radius.

A laser diode with an output beam contained in the active layer by means of a built-in refractive index profile formed in that layer or in the adjacent cladding layers or both.

A material, often a liquid or cement, whose refractive index is nearly equal to the fiber's core index, used to reduce Fresnel reflection from a fiber end face.

A mirage that consists of an image of an object appearing below its true position as the result of abnormal refraction by the atmosphere between the object and the viewer. It is the opposite of a...

A direct method of measuring refractive index that works best with flat-surfaced samples (i.e., those that are not dependent on special prism shapes) and produces data that are uniquely sensitive to...

1. The additive process whereby the amplitudes of two or more overlapping waves are systematically attenuated and reinforced. 2. The process whereby a given wave is split into two or more waves by,...

Measures the refractive indices axially from the fiber profile. Microscopy technique provides an interferogram with high contrast with demonstrated improvements in relation to the Pluta two-beam...