Photonics Dictionary

A subsurface imaging technique based upon the polarization of light reflected off an object. The polarization of reflected light gives information about the object's absorption properties that...

A photometer having a pair of Nicol prisms introduced into the beam from the brighter of two sources to be compared. Turning one of these polarizers reduces the beam to equality with the beam of the...

Capability requirement for optical switches for transmission lines to process arbitrarily polarized light because of the rapid changes in the polarization state of light propagating in the fibers.

Single-mode fiber that preserves the plane of polarization of the light launched into it as the beam propagates through its length. Also called polarization-maintaining fiber. The polarization is...

An optical device capable of transforming unpolarized or natural light into polarized light, usually by selective transmission of polarized rays.

A mold for glass or plastics often made of stainless steel to prevent pitting or oxidation in service. It is polished to the opposite curve of the surface that will be molded, and may be spherical or...

A flat cylindrical device generally used to polish terminated ends in fiber optic connections.

Inquiry made to gain access by a master station in a token ring network.

A tough, durable, heat- and cold-resistant optical quality plastic used in injection-molded items such as streetlight lenses, automotive taillights and audio compact discs.

Light that is a mixture of wavelengths.

A polygonal mirror, also known as a multifaceted mirror or facet mirror, is a type of optical component used in various laser systems, optical scanners, and imaging devices. It consists of a flat or...

Polymers are large molecules composed of repeating structural units called monomers. These monomers are chemically bonded together to form long chains or networks, creating a macromolecular...

The polymerase chain reaction (PCR) is a widely used molecular biology technique used to amplify a specific segment of DNA (deoxyribonucleic acid) through a series of temperature-controlled cycles....

Process of synthesizing long molecular chain materials (polymers) by reaction of many small molecules (usually thousands) called monomers.

The condition in which there are more atomic systems in the upper of two energy levels than in the lower, so stimulated emission will predominate over stimulated absorption. This condition may be...

A 45-90-45° reflecting prism whose surfaces form the 90° angle reflecting the light beam through a total angle of 180°. The corners of the prism are rounded to minimize breakage and simplify...

Positioning generally refers to the determination or identification of the location or placement of an object, person, or entity in a specific space or relative to a reference point. The term is used...

A medical imaging device that uses a ring of crystal/photomultiplier tube assemblies encircling the patient to detect gamma rays emitted by positrons colliding with electrons.

Basically, a hydrogen atom with two alterations, positronium is the lightest atom in the universe and has an extremely light positron in its nucleus that replaces hydrogen's proton so that its atomic...

In image processing, the effect caused by large jumps between gray levels, rather than a gradual change.

A crystalline material with a high electro-optic coefficient, capable of operating at short wavelengths, with applications in laser, optical disc, printing and microwave systems.

A camera system that uses a fine powder to diffract x-rays from the specimen. A beam of monochromatic x-rays passes through a collimator onto the specimen. Diffracted x-rays are recorded on the film...

A technique used in radiography to determine a crystal's structure by obtaining radiographs of it in powder form, normally by the use of a powder camera that forms an image of the crystal's x-ray...

With respect to a lens, the reciprocal of its focal length. The term power, as applied to a telescope or microscope, often is used as an abbreviation for magnifying power.

In laser welding or heat treating, the instantaneous laser beam power per unit area. This parameter is key in determining the fusion zone profile (area of base metal melted) on a workpiece.

Optical fiber channel characterization scheme based on three assumptions; the discrete mode spectrum can be replaced by a continuum; the loss due to coupling between guided and radiation modes...

Power modulation refers to the intentional variation of power levels in a signal, often in the context of electronic communication systems. This modulation technique is used to encode information...

Laws that predict the maximum power output as a function of tube diameter for a hydrogen cyanide laser of a given discharge length and cavity losses, all other parameters being optimized.

A filtering method that restores a blurred image by setting its power spectrum equal to that of the original image.

Refers to the voltage and current necessary for the operation of circuit devices.

In remote sensing technology, this represents the intensity of energy flow in the direction of wave propagation.

A transition boundary between two regions having different properties in a P-type semiconducting material.

Ratio of the molecular diffusion coefficients of momentum in terms of heat; used in convection studies.

An accurately produced hole of any size and shape that is used as a masking device in an optical system. Pinhole apertures of accurate diameters often are produced by laser beam penetration or by...

A step before fusion splicing that involves cleaning the fiber end with low-current electricity.

A state in which the human eye has very little or no power of accommodation. A common and normal condition in the eyes of those age 50 and older.

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.