Photonics Dictionary

Transparent matter that usually is drawn into a cylindrical, pyramidical or conical shape through which light is channeled from one end to the other by total internal reflections. Optical fibers are...

Also known as single plane illumination microscopy (SPIM), this process was designed for imaging of sensitive samples and fast biological processes in vivo. In this method, a light sheet illuminates...

The fraction of incident light power in an optical modulator that is available to the output beam.

With respect to display systems, a device that uses an independent light source and a control-layer medium, the active optical element, to convert an electrical charge image to an optical image....

The spectroscopic analysis of optical line shapes and frequency shifts, using the technique of light beating; i.e., the mixing of two narrowband optical components to produce an AC component in the...

The angle subtended by two points or lines that are just far enough apart to be distinguished as separate. The ability of an optical device to resolve two points or lines is called resolving power...

The line of vision; the optical axis of a telescope or other observation system. The straight line connecting the object and the objective lens of the viewing device.

In the spectral sense, an optical source that emits one or more spectrally narrow lines as opposed to a continuous spectrum. In the geometric sense, an optical source whose active (emitting) area...

A term for thermoplastic optical materials; that is, those in which the polymer chains remain linear after heating and molding and which thus can be remolded again and again, unlike thermoset...

Linear polarization refers to the polarization state of light where the electric field oscillates in a single plane as the light propagates through space. In other words, the electric field vector of...

A linear positioning stage, also known as a linear stage or translation stage, is a precision mechanical device used to accurately move and position objects along a linear axis. These stages are...

Linewidth, also known as spectral linewidth or line width, refers to a measure of the width of a frequency spectrum of a signal or a resonance. It indicates the range of frequencies over which the...

A defect in the cleaved end face of an optical fiber, in the form of a sharp protrusion at the edge of the fiber.

A self-healing, index-matching, nonporous coating for optical components that can eliminate production difficulties and deficiencies associated with solid-film contamination and postdeposition...

Multimode straight fiber capable of transporting linearly polarized light with any incident polarization angle, and in which no form of internal stress can develop that could lead to birefringence.

Liquid crystals are a state of matter that exhibits properties intermediate between those of conventional liquids and solid crystals. In a liquid crystal, the molecules are ordered like those in a...

A liquid crystal light valve (LCLV), also known as a spatial light modulator (SLM), is an optical device that modulates the intensity, phase, or polarization of light passing through it using liquid...

Liquid crystal on silicon (LCoS) is a display technology that combines liquid crystal materials with silicon-based semiconductor technology to create high-resolution, high-quality images. LCoS...

An immersion liquid used to treat polarizing filters to eliminate the effects of surface variations and to minimize the optical path difference between that part of the spectrum that passes through...

An optical fiber with a hollow core filled with a liquid material that has a higher refractive index than the solid surrounding it.

A crystalline ferroelectric material used primarily as a substrate and an active medium for thin-film optical modulators and switches. It possesses very high electro-optic and piezoelectric...

Lithium triborate, commonly abbreviated as LBO, is a nonlinear optical crystal widely used in various applications involving frequency conversion of laser light. It is valued for its excellent...

A device used to evaluate the quality of fiber optic splices made in the field by injecting light into the cladding of the fiber and measuring the output at the other end of the splice.

In coherent optical communications systems, a laser used at the receiving end to produce a steady wave that is combined with the incoming laser signal before detection, generating a composite wave...

A fiber optic component or system designed in such a way that it can be operated by people without specialized knowledge of the field.

A long-pass filter is an optical filter that allows longer wavelengths of light to pass through while blocking or attenuating shorter wavelengths. These filters are designed to transmit light with a...

In fiber optic communications systems, generally one that operates between 1000 and 1700 nm.

Pockels cell or dynamic optical retarder in which the electrical field is applied in a direction parallel to that of light passing through it.

In fiber optic cable, containment of the fiber or fibers within an outer protective tube in which they can move to some extent. The interstices usually are filled with an insulating material. See...

The Lorentz oscillator model is a theoretical model used in physics to describe the response of a charged particle (such as an electron) to an oscillating electric field. It is particularly employed...

The total optical power loss in a system. The loss budget is often stated in terms of the transmitted power and the power required at the receiver to express the maximum acceptable amount of loss.

Term used to describe an optical surface that contacts the test glass only at its edges.

Optical fiber that transmits a greater percentage of input light than does high-loss step-index fiber. Low-loss fiber requires higher purity materials and a more sophisticated drawing process and...

A photometric instrument having two prisms clamped in optical contact to produce a photometric field with an acute dividing line.

A Mach-Zehnder interferometer is an optical device used to measure the phase difference between two collimated beams of light. It is named after the physicists Ludwig Mach and Ludwig Zehnder, who...

A machine vision lens is a specialized optical lens designed for use in machine vision systems, which are used for automated inspection, measurement, and quality control in industrial applications....

A machine vision system is an integrated combination of hardware and software components designed to capture, process, and analyze images to perform automated inspection, measurement, and quality...

In an optical waveguide, that loss attributable to macrobending. Macrobending usually causes little or no radiative loss.

In optical fiber, bends that are larger than microbends (see microbending), being visible. Generally they are caused by bending the cable beyond the specified bend radius. Light escaping at the bends...

An amorphous film in which cylindrical bubbles of reverse magnetization can be formed to follow circuit paths usually made by depositing magnetic metal strips on the film surface. It is used in...

Plasma-enriched deposition or planar magnetic sputtering that offers increased deposition rates in optical thin-film production. This technology surpasses conventional and RF sputtering.