Definitions

Denoting a phase shift of 90°.

Quantum sensing refers to a class of sensing technologies that leverage principles from quantum mechanics to enhance the precision and sensitivity of measurements. Traditional sensors operate based...

A plate made of a double-refracting crystal having such a density that a phase difference of one-quarter cycle is formed between the ordinary and extraordinary elements of light passing through.

The degree of angular shift in the phase of incoming polarized light.

The phase change of one of the two split beams of an interference microscope.

A device that uses nematic liquid crystals sandwiched between fused silica substrates to change the phase of polarized light. The cell is tunable from half-wave to zero retardation because variation...

A ring laser gyroscope (RLG) is a type of gyroscope that uses laser light to detect and measure changes in orientation. It operates based on the Sagnac effect, which is a fundamental principle of...

An interferometric method for describing the surface shape of large coated or uncoated optical flats. The procedure uses a commercially available small-aperture phase-shifting interferometer for...

A type of interferometer in which two coils of optical fiber are arranged so that light from a single source travels clockwise in one, and counterclockwise in the other. Rotation of the coils causes...

An optical compensator similar to the Babinet compensator, but which produces a phase-change consistent throughout its field, as opposed to the Babinet's phase-change, which occurs progressively...

The maintenance of a fixed-phase relationship across the full diameter of a cross section of a laser beam.

Spatial light interference microscopy (SLIM) is an optical microscopy technique that belongs to the category of quantitative phase imaging methods. It is designed to provide high-resolution,...

A spatial light modulator (SLM) is an optical device that modulates or manipulates the amplitude, phase, or polarization of light in two dimensions, typically in the form of an array. SLMs are...

The correlation of radiation between the phases of monochromatic radiation emanating from two separate points.

An instrument that divides a single laser beam in two and uses one half as a sensing beam and the other as a reference beam, then recombines the two and measures any phase shift between them. The...

A phenomenon that causes the details in an image to appear at a spatial frequency higher than that at which the contrast first drops to zero. A phase reversal will accompany this phenomenon, often...

Radiation similar in origin to spontaneous emission but determined by the presence of other radiation having the same frequency. Because the phase and amplitude of the stimulated wave depend on the...

Supercontinuum refers to a broad spectrum of light that spans a wide range of wavelengths, typically from the visible to the near-infrared or even mid-infrared regions of the electromagnetic...

A liquid crystal display using the material in its supertwisted nematic phase; the birefringence of the liquid crystal results in a characteristic yellow or blue color, unless corrected.

A detector sensitive only to signals close to or at a particular frequency that is the same as the frequency of a control signal applied independently. The synchronous detector also is...

A mode of transmission whereby the sending and receiving stations operate continuously at a fixed relationship of phase and frequency, generating signals to control the timing of the data that are to...

Thermal interface materials (TIMs) are substances or compounds used to enhance the thermal conductivity between two surfaces in contact. These materials are primarily employed in electronic devices,...

The complex function, H(f), equal to the ratio of the output to input of the device as a function of frequency. The amplitude and phase responses are, respectively, the magnitude of H(f) and the...

In the context of optics and lasers, a transverse mode refers to a specific spatial pattern of the electric field within the cross-section of a laser beam. These modes represent the different...

A method of measuring negatively charged phase ions using a color-center or lead-salt diode laser.

A phase-shift interferometer used to detect the relative angular speeds or positions of two concentric rotors.

For each mode in an optical waveguide, the term used to describe the process by which an electromagnetic signal is distorted by virtue of the dependence of the phase and group velocities on...

A device that consists of two types of mode converters, one of which must be magnetic. It is nonreciprocal because the coupling constants of the two mode converters have a different phase relation...

The Weissenberg method, named after the German physicist Karl Weissenberg, is a technique used in x-ray crystallography for obtaining high-quality diffraction patterns from single crystals. This...

The difference in electrokinetic potential between the stationary liquid connected to a solid phase surface and the mobile portion of the liquid's diffuse layer.