Photonics Dictionary: P

A substance that transmits the infrared, but which is too delicate or fragile to be used in the form of a single crystal. Instead, the pure material is finely ground, pressed to the required shape,...

A material used to jacket fiber optic cables. It is chemical- and moisture-resistant, but not fire-resistant.

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.

A plastic used in molded optical components. Styrene elements can be combined with acrylic elements to produce achromatic lenses.

A thermoplastic, self-extinguishing polymer with excellent high-temperature, low-creep and arc resistance properties.

An optical-quality polymer used in birefringent retarders.

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...

The arrangement of two Porro prisms so that the inverted image formed by certain types of optical instruments is the same as the object. The first prism, which is set at 90° to the second, inverts...

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 uniaxial, birefringent crystal having an ordinary ray with a higher velocity than the extraordinary ray.

The dielectric coefficient parallel to the director in a liquid crystal display (LCD), rather than perpendicular to the director.

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 device designed to measure electromotive force or electrical difference potential.

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.

For a pulsed laser, the product of the energy per pulse (joule) and the pulse frequency (hertz); expressed in watts.

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.

The ratio of emitted power to input power.

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.