Photonics Dictionary

Photoelastic equipment and supplies refer to instruments and materials used in photoelasticity, a technique used to analyze stress distribution and behavior in materials. photoelastic equipment...

A photon jet is a narrow, highly collimated beam of light that is formed when light interacts with small dielectric microstructures, such as microspheres or microcylinders. This phenomenon arises due...

Photonic crystals are artificial structures or materials designed to manipulate and control the flow of light in a manner analogous to how semiconductors control the flow of electrons. Photonic...

A material in which the refractive index varies according to changes in the light to which it is exposed. Lithium niobate is one example.

The use of a plasma to induce the formation of oxides in the production of graded-index optical fibers.

Plastic optical fiber (POF) is a type of optical fiber made from transparent plastic, typically polymethylmethacrylate (PMMA) or polycarbonate. Unlike traditional glass optical fibers, which are made...

In optics, the Pockels effect refers to the phenomenon where the refractive index of a material changes in response to an applied electric field. This effect is utilized in Pockels cells, which are...

A Pockels cell, also known as an electro-optic modulator, is an optical device used to control the polarization of light by applying an electric field. It is named after the physicist Friedrich Carl...

A device attached to the end of an alignment telescope that detects and calculates a plane mirror's rotation axis that is perpendicular to the line of sight. The device is adaptable for evaluation of...

Injecting a gas (usually nitrogen) with a very low moisture content into the body of an optical instrument to create a positive internal pressure. This prevents the entrance of moisture, which could...

Also referred to as primary color, this is the classic chromatic aberration of a single element caused by the variation of index of refraction as a function of wavelength.

The chromatic resolving power of a prism is invariably stated for the case in which parallel rays of light are incident on the prism, in which the prism is oriented at the angle of minimum deviation...

An instrument that measures the angle at which a prism can couple laser light into an optical waveguide; used to determine the thickness and refractive index of thin films in integrated optical...

A prism is a geometric optical element with flat, polished surfaces that refract light. It is typically a solid, transparent object with at least two flat surfaces that are inclined relative to each...

In an optical waveguide, that dispersion attributable to the variation of refractive index profile with wavelength. The profile variation has two contributing factors: variation in refractive index...

Factor that relates the pulse spread occurring in a graded-index fiber to that of an equivalent step-index fiber having an identical refractive index difference between core and cladding (that is, an...

Quantitative phase imaging (QPI) is an advanced imaging technique used in microscopy to measure and analyze the optical phase information of transparent specimens. Unlike traditional brightfield...

In gradient index optics, a gradient profile in which the index varies in a direction perpendicular to the optical axis. Radial gradient lenses can focus light even when the lens surfaces are flat,...

Plates of glass containing as many heavy metal oxides as can be dissolved in the glass without causing devitrification. The glass is yellow, very heavy and has a high refractive index. It is almost...

Optical glasses containing the oxides of rare earths such as lanthanum to impart a very high refractive index combined with a low dispersive power.

A device that is used to determine the index of refraction of a gas or liquid through the interference patterns formed by two beams of light, one of which has been transmitted by the sample. A single...

A nonhomogeneity of index in flat glass that is in the form of an approximately plane layer.

Straight line travel. This denotes the fact that light travels in a straight line when traveling through a medium with a constant refractive index.

The ratio of the first focal length of a lens to the refractive index of the medium containing the incident light; the ratio of the second focal length to the refractive index of the medium...

The technique for measuring the index profile of an optical fiber by scanning the entrance face with the vertex of a high numerical aperture cone and measuring the change in power of refracted...

A transparent sphere that has an index of refraction that is different from that of the medium surrounding it; used in optics to demonstrate refraction and astigmatic image formation.

The bending of oblique incident rays as they pass from a medium having one refractive index into a medium with a different refractive index.

An instrument used to measure the refractive index of solids and liquids. Several types exist, the most common being the Abbe refractometer.

The method used to determine the refractive index of a given substance.

Sapphire refers to a crystalline form of aluminum oxide (Al2O3) that is used in various optical and photonic applications due to its exceptional optical, mechanical, and thermal properties. Sapphire...

The formation of a picture or image in which the density gradients in a volume of flow are rendered visible. The image is formed by refraction and scattering from areas of varying refractive index.

In multifocal spectacles, a term used to denote glass with a high refractive index that has been fused to the blank and ground to a curvature, resulting in added power.

Self-phase modulation (SPM) is a nonlinear optical phenomenon that occurs when an intense laser beam passes through a medium, causing a change in the phase of the light due to its interaction with...

Derived from "self-focusing,'' Nippon Sheet Glass Co. (NSG) of Japan's trade name for graded-index fiber rods with parabolic index profile, suitable for use as cylindrical microlenses.

An equation that uses the wavelength of light passing through a medium, along with a set of coefficients, to calculate the medium's index of refraction. The coefficients, called Sellmeier...

The method for measuring the index profile of an optical fiber by preparing a thin sample that has its faces perpendicular to the axis of the fiber, and measuring its index profile by interferometry.

A beam instability, induced by index of refraction inhomogeneities and component damage of dirt and dust particles, that exhibits exponential growth and causes both system degradation and energy loss...

Spatial light interference microscopy (SLIM) is an optical microscopy technique that belongs to the category of quantitative phase imaging methods. It is designed to provide high-resolution,...

In gradient index optics, a gradient profile in which the refractive index varies symmetrically about a point.

The refraction that would take place in an idealized atmosphere where the refractive index is reduced uniformly with height at the rate of 39 x 10-6 per kilometer.