Photonics Dictionary: P

Acronym for profile resolution obtained by excitation. In its simplest form, probe involves the overlap of two counter-propagating laser pulses of appropriate wavelength, such that one pulse...

A probe card is a testing device used in the semiconductor manufacturing industry to evaluate and test the electrical characteristics of integrated circuits (ICs) on a wafer. Its primary function is...

The collection and analysis of data relevant to monitoring the rate and quality of industrial production, either continuously or in batches. Corrections can be made manually or automatically, via a...

A lens that is symmetrical and designed to work between 1:1 and about 4:1. It covers a field of about ±20° at f/8 or f/10, and may have a focal length up to about 30 in., although the usual...

A superposition of many zone plates, each reconstructing a real and virtual point image at the appropriate locations upon illumination by a reference beam.

In an optical waveguide, that dispersion attributable to the variation of refractive index profile with wavelength. The profile variation has two contributing factors: variation in refractive index...

Measurement of surface roughness or quality through the use of a diamond-pointed stylus connected to a coil in an electric field. As the stylus is traced across the surface, a current is created that...

In computerized industrial process control, the element that determines the choice and sequence of operations dependent on varying conditions.

A contour mapping technique that involves projection of a grating onto an object to produce a shadow grating that is observed through another grating. Therefore, the size of the object to be measured...

Technique using a fiber optic assembly to illuminate an opaque object and transmit an image back from it without a lens system on the distal end.

A method used to approximate the values of the homogeneous second derivatives at each iteration in the course of lens design and that excels the rate of convergence of the damped least squares method...

An astronomical body that emits radiation concentrated by a strong magnetic field into two beams that rotate, giving a pulsing effect.

The instrument used to analyze a pulsed electromagnetic wave to determine its time, amplitude, duration and shape, and to display this information in some appropriate form, either visually or...

System of information coding in which the signal is sampled 8000 times per second and the samples quantized by referring them to a series of preset 8-bit codes. Thus digitized, the signal is sent to...

A series of capacitors and inductors connected to the flashlamp in a pumped Nd:YAG laser system in order to regulate the pulse shape of the current delivered to the lamp at a given operating voltage.

Factor that relates the pulse spread occurring in a graded-index fiber to that of an equivalent step-index fiber having an identical refractive index difference between core and cladding (that is, an...

An instrument designed for laser technology that is used to extract single pulses from the laser and transmit a portion of the pulses, thereby reducing the pulse rate to a desirable frequency.

Variations in a signal passing through an optical fiber caused by the effect on the pulse of the fiber's material and mode propagation characteristics.

A noncontact, nondestructive method of measuring defects in thin composite materials, using a xenon flashtube to generate heat in a sample. A thermal imaging system detects differences in the rates...

A laser that emits energy in a series of short bursts or pulses and that remains inactive between each burst or pulse. The frequency of the pulses is termed the pulse-repetition frequency.

A technique for depositing a material coating on metal, ceramic, semiconductor or polymer substrates. The interaction of laser energy with the target creates a plume of ablated material that is...

A laser with a gain medium consisting of an organic dye, which is carbon-based. The dye is mixed with a solvent, allowing the molecules to diffuse evenly throughout the liquid. The dye medium is...

A group of energy levels to which ions in the ground state are initially excited when pumping radiation is applied to a laser medium. The pumping band usually lies higher in energy than the levels...

1. In the eye, the opening in the iris that permits light to pass and be focused on the retina. 2. In a lens, the image of the aperture stop as seen from object and image space.

An instrument for measuring the diameter of the human eye pupil.

Pushbroom scanning is a technique used in remote sensing and imaging systems, particularly in satellite and aerial sensors, to capture images of the Earth's surface or other objects. In pushbroom...

Pyramid error in optics refers to an aberration in the shape of an optical surface, particularly in the context of mirrors. It is a type of distortion that can occur when the surface of a mirror...

Trade name for a type of borosilicate glass manufactured by Corning Glass Works, noted for its low coefficient of thermal expansion. Used most often for mirror blanks; not suitable for light...

An instrument for measuring the intensity of solar radiation.

Unlike the thermocouple or bolometer, the pyroelectric infrared detector is a current source with an output proportional to the rate of change of its temperature. Capable of extremely rapid response...

A current-source thermal detector used to detect and study the pulses obtained from particular lasers.

A process that employs heat to remove polyimide plastic coatings from silica optical fibers and capillary tubing.