Photonics Dictionary: B

A lens having each of its outer faces curved inward.

A lens having each of its outer faces curved outward.

It is often necessary to estimate the value of what a pixel would be between neighboring pixels. This is accomplished by interpolating (or inserting) the value of a pixel between neighboring pixels....

An experimental lens used to produce interference fringes. A positive lens is cut into halves along its center, and the halves are separated. This produces a double image of a slit source set...

Signal used in optical transmission systems to generate currents in a detector that are decoded with reference to a specified threshold.

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....

Bioluminescence is a natural phenomenon in which living organisms produce and emit light through a chemical reaction occurring within their bodies. This light emission is typically the result of a...

A biomarker, short for biological marker, refers to a measurable and quantifiable indicator of a biological condition, process, or response. Biomarkers can be substances or characteristics that are...

Biometrics refers to the automated recognition of individuals based on their physiological or behavioral characteristics. These unique attributes are used to verify or identify individuals, often in...

The technology that deals with the interaction of organic materials with light and other forms of radiant energy whose quantum unit is the photon. This includes the emission, detection, absorption,...

Also called proximity focus image intensifier. A compact image intensifier that utilizes a microchannel plate intensification stage. This is an in-line device that does not invert the image.

Refers to transistors in which the working current flows through two types of semiconductor material: N- and P-type. In bipolar transistors, the working current consists of both positive and negative...

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 filter that transmits light in a series of sharp, widely spaced wavelength bands by its sandwich construction of alternating layers of polarizing films and plates cut from birefringent crystal.

A data transfer function that moves a rectangular group of pixels between bit maps. Often used in displaying cursors and pop-up windows.

In ophthalmic practice, an instrument that determines the boundaries of the field of view. It is composed of a 2-m square of black velvet with a white spot center at which the patient, 1 m away,...

A blackbody source, often simply referred to as a blackbody, is a theoretical or practical physical object that absorbs all electromagnetic radiation incident upon it and emits radiation in a...

A piece of glass, quartz or other transparent material formed roughly by molding or cutting into the approximate shape and size of the finished part.

The process by which the raster beam in a video tube is cut off during the retracing and sync periods.

The inability to perceive visual images (visible radiant energy). In human beings, blindness is defined as a visual acuity of less than one-tenth normal vision.

The loss of focus of a camera sensor because of excessive brightness, characterized by the enlargement of spot size and halation on a cathode-ray tube.

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...

A Bose-Einstein condensate (BEC) is a state of matter that forms at temperatures close to absolute zero. It is named after Satyendra Nath Bose and Albert Einstein, who independently predicted 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...

In photography, the technique of taking multiple pictures of the same subject at different exposures to compensate for exposure miscalculations. Automatic bracketing is a feature on some cameras.

A technique in which a beam of x-rays is directed against a crystal, the atoms of which, because of their lattice arrangement, reflect the ray in the same way as a series of plane surfaces. If the...

The scattering of x-rays by the regularly spaced atoms in a crystal. The angle at which the reflection occurs is known as the Bragg angle.

The law expressing the condition under which a crystal will reflect a beam of x-rays with the greatest amount of distinction or resolution and, at the same time, denoting the angle at which the...

A sheet of thin brass, one edge of which has been accurately cut to a known and marked circular radius. It is used to check the radius of curvature of a rough-ground lens by contact.

An experimental model of an electrical circuit or complex assembly; a prototype.

In avalanche photodiodes, the point at which an increase in the reverse bias voltage causes the current gain to approach infinity.

Theoretical calculation of the cross section for a nuclear reaction given in the vicinity of a single resonance level in the compound nucleus.

A parallel plate of glass in such a position that the refracted and reflected rays of incident parallel light are mutually perpendicular. In this situation the reflected light is plane polarized, and...

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...

A broadband filter is an electronic or electromagnetic device designed to pass a range of frequencies or signals within a specified bandwidth while attenuating or rejecting signals outside of that...

Radiation that occurs perpendicular to the plane of the radiation device.

A surface imperfection caused by a polisher running dry too long. It occurs with felt or plastic polishers, and may appear as a reddish brown.

A convex lens that brings an incident bundle of rays to a focus to produce intense heat at the focus.

The measure used in vacuum technology to quantify the total pressure capacity of the ferrofluidic seal before it fails.