Search
Menu
Photonics Marketplace
304 terms

Definitions: B

Clear All Filters xDefinitions xB x
Becquerel effect
The intensification of a latent image, because of exposure to light to which the emulsion is otherwise insensitive.
Beer's law
Transmittance of a stable solution is an exponential function of the concentration of the absorbing solute.
Beer-Lambert law
Combination of Beer's and Lambert's (absorption) laws.
bellows
In optics, a collapsible structure situated between the lens and film of a camera to allow variation of the distance between them while preventing surrounding light from exposing the film.
bench -> optical bench
A support for optical parts comprising a solid bed that permits precise longitudinal movement of one component relative to the others, and a number of sliders equipped with holders for lenses, lamps,...
bench photometer
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...
bend -> deformation constant
Any of the constants that relate the tendency of the director to remain parallel to restoring torques throughout the media. The three constants of importance in liquid crystal displays are: splay --...
bend loss
The loss of optical power in an optical fiber because radiation escapes through its bends. The radiation loss caused by fiber bending is proportional to the bend radius.
bend radius
The radius of curvature that an optical fiber can bend without breaking.
bending of light
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...
Bernoulli terms
Mathematical definition for the changes that occur between potential and kinetic energy. These formulas express wave motion.
Bertrand lens
A small convergent lens, located between the objective and eyepiece of a microscope, that focuses an image of the upper focal plane of the objective in the focal plane of the eyepiece. It is commonly...
beryllium oxide
A dielectric ceramic material used in laser capillary tubes because of its high electrical resistivity and high thermal conductivity (half that of copper).
Bessel functions
Two formulas used in diffractometer analysis, the first giving the individual diffraction patterns of each aperture, the second representing the constant of the degree of an incoherent circular...
beta fluorography
The use of a short-duration electron beam to record high-speed events that occur in microscopic objects made of materials that emit visible fluorescence during electron bombardment. The method is...
beta radiation
The high-speed electrons and positrons emitted by radioactive materials.
beta site
A facility selected by mutual agreement of the user and the prospective vendor to test a prototype before it is offered for sale.
beta-ray spectrometer
An instrument for the detection of the energy distribution of b-particles and secondary electrons.
betatron
An instrument designed to produce very hard x-rays by the acceleration of electrons in a varying magnetic field.
bevel
A chamfer ground on the edge of a lens or prism. Bevels are used to prevent chipping or to achieve a mechanical fit.
bevel face width
The actual width of a bevel rather than its width projected along the lens aperture.
bi-quartz
A double block formed by placing two adjoining, equally thick sections of quartz, one being dextrorotary, the other levorotary, over the analyzer of a polariscope. In this way, polarization tints may...
bias
1. To influence to a single direction. 2. Voltage that is applied to a solid-state device.
bias buildup
Degradation factor in coherent light systems where the amplitude of the recorded signal is decreased as the number of object points is increased, resulting in poor noise performance.
bias frame
A frame taken with a CCD camera over an exposure length of zero seconds with the lens cap on or the shutter closed and no light reaching the sensor. This frame shows the electronic noise in the...
biaxial crystal
A birefringent crystal having two axes along which there is an absence of double refraction. Mica, sulphur and turquoise are biaxial crystals.
Biberman factor
Mathematical compensation for the nonhydrogenic behavior of recombination radiation levels of gases, based on the quantum effect method.
biconcave lens
A lens having each of its outer faces curved inward.
biconic connector
A type of fiber optic connector consisting of two cone-shaped ferrules aligned by a mating sleeve.
biconvex lens
A lens having each of its outer faces curved outward.
bidirectional reflectance distribution function
Unified notation for specification of reflectance in terms of both incident- and reflected-beam geometry; i.e., the ratio of reflected radiance in direction toward the viewer to the irradiance in...
bifocal lens
A two-part lens that has a different focal length for each part. Generally, it is used in eyeglasses to correct for both near and far vision.
bifurcated fiber
A branched fiber optic lightguide that performs both receiving and transmitting functions.
bilinear interpolation
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....
Billet's split lens
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...
bimorph
A type of piezoelectric translator that uses two thin strips of piezoelectric material, one expanding while the other contracts, to produce movement.
binary digit -> bit
binary digit
binary image
A digitized image consisting of just two brightness levels, as black and white, represented in memory as zeros and ones.
binary on-off
Signal used in optical transmission systems to generate currents in a detector that are decoded with reference to a specified threshold.
binary optics
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....
binary phase-only filtering -> phase-only filter
A type of matched filter that responds only to the phase of incoming light; the output has a much greater intensity than that of a classical matched filter, which responds to phase and amplitude. The...
binary thresholding
An imaging technique that labels all gray pixels as either black or white before processing begins.
binning
Combining adjacent pixels into one larger pixel, resulting in increased sensitivity and lower resolution, or, in image analysis, excluding objects based on shape, position or area.
binocular collimation
The adjustment of a binocular instrument so that the lines of sight of both telescopes are parallel.
binocular luster
The glossy appearance of an object viewed, because of the binocular combination of two very unlike colors.
binocular magnifier
A device having a pair of decentered lenses, one for each eye, that focuses on a single object as a magnifier. It is often supplied with a forehead fixture or an elastic headband to leave the hands...
binocular microscope
A microscope designed with two eyepieces (oculars), permitting the use of both eyes when viewing through the instrument.
binocular parallax
The difference in angular bearing of an object as seen by the two eyes, due to the separation of the visual optical axes.
binocular threshold
The absolute luminance threshold for detection by the two eyes.
binocular vision
The ability of the two eyes to see an object from two slightly different points of view. This difference allows an individual to perceive the depth and dimension of the object in view.

Photonics DictionaryDefinitionsB

We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.