Photonics Dictionary: B

Calculates the exponential growth of the least stable spatial frequency in a laser beam, and is the numerical equivalent of the nonlinear phase shift along the laser system's optical axis.

A light-harvesting protein found in the purple membrane of a micro-organism called Halobacterium halobium. The protein undergoes a photocycle that involves several binary photochemical reactions that...

An opaque shielding device designed to reduce the effect of stray light on an optical system.

A ball lens is a small, spherical optical component typically made of glass or other transparent materials. It is characterized by its spherical shape, with both its front and back surfaces forming...

A relatively hard crystal, highly resistant to excessive energy radiation, that is frequently used for optical windows, prisms and lenses transmitting from the vacuum UV into the IR.

Beam profiling is a technique used to characterize and analyze the spatial intensity distribution of a laser beam. It involves measuring and visualizing how the optical power or intensity is...

A beam shaper is an optical device or system designed to modify the spatial profile or intensity distribution of a laser or light beam. The goal is to transform the incoming beam into a desired shape...

A beamsplitter is an optical device used to divide a beam of light into two or more separate beams, typically by reflecting a portion of the incident light while transmitting the remainder....

The angular width of a radiation beam. With respect to a conical beam of light, it is the vertex angle of the cone. The beamwidth is a measure of the rate of divergence or convergence of a light...

A characteristic of optical fiber used to calculate the fiber's ability to maintain polarization. The beat length describes the length required for the polarization to rotate 360 degrees. For a given...

A device used to compare the luminous intensities of two sources by locating a point between the two light sources where the produced flux densities are equal. The luminous intensities of the two...

The radius of curvature that an optical fiber can bend without breaking.

1. That action occurring when light passes through an optical interface at other than normal incidence, i.e., refraction. 2. The curving of a path of light that passes close by a massive object, due...

Optical elements, often created by micromachining, lithography or vacuum deposition, that rely on diffraction of the collected energy as opposed to the more common refracting or reflecting optics....

The difference in angular bearing of an object as seen by the two eyes, due to the separation of the visual optical axes.

A term pertaining to devices (generally optical) designed for use with both eyes viewing through a single exit pupil. The term may be distinguished from binocular in that biocular instruments contain...

Birefringence is an optical property of certain materials that causes them to exhibit different refractive indices for light of different polarizations. In other words, when light passes through a...

A photorefractive material used in image processing, holography and optical switching.

Blaze height typically refers to a parameter in the context of diffraction gratings, which are optical devices consisting of a series of closely spaced parallel grooves or slits. The blaze height is...

An adhesive used to hold optical elements to blocking tools. It is usually a thermoplastic substance such as resin, beeswax, pitch or shellac.

An adhesive used to affix optical elements to an approximately shaped body -- usually of cast iron.

A convex, concave or flat cast iron form that is used to shape a soft mold block of optical components.

A technique developed by British Telecom in which the viscous drag of air is used to install optical fibers in narrow plastic tubes.

A blue diode laser is a type of semiconductor laser that emits light in the blue wavelength range of the electromagnetic spectrum, typically between 400 and 500 nanometers. Diode lasers are compact,...

A blur circle refers to the out-of-focus region in an image captured by an optical system. When an object in a scene is not in perfect focus, its image is spread out into a circular shape on the...

1. A group of optical fibers that are fused and then treated to produce a vacuum-tight optical fiber cone or plate. 2. An artificial crystal in its raw state, after generation but prior to cutting or...

A filter that separates light into many colors via Bragg's law. Generally refers to a fiber Bragg grating used in optical communications to separate wavelengths.

An optical image having a brightly lit background.

Brillouin scattering is a phenomenon in physics where an incident electromagnetic wave (usually light) interacts with acoustic phonons (quantized lattice vibrations) in a material, resulting in the...

Broadband dielectric mirrors, also known as broadband mirrors, are optical coatings designed to efficiently reflect or transmit light over a broad range of wavelengths. These mirrors are constructed...

An optical instrument designed to permit the visual examination of the interior of the bronchi.

A large tank filled with liquid hydrogen, with a flat window at one end and complex optical devices for observing and photographing the rows of fine bubbles formed when a high-energy particle...

1. In fiber optics, a protective material applied as an optical fiber cover that has no optical function. 2. In image processing, a peripheral that stores data between two active processing stages.

The production of a block by attaching the optical elements to a plate by means of individual buttons of pitch or other thermoplastic material.