Photonics Dictionary

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...

Twyman-Green interferometry is a technique used in optics to measure the flatness or surface profile of optical components with high precision. It is based on the principles of interference of light...

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.

A waveform is a graphical representation of the shape and magnitude of a signal over time. It typically depicts how the amplitude (strength) of the signal changes over time, with time plotted along...

A wavefront refers to the continuous surface or boundary representing points in a wave that are in phase, meaning they have the same phase or position in their respective cycles. In simpler terms,...

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.