Photonics Dictionary

A thin layer of a substance deposited on an insulating base in a vacuum by a microelectronic process. Thin films are most commonly used for antireflection, achromatic beamsplitters, color filters,...

Thin-film coatings are layers of material applied to the surface of an object or substrate, typically to modify its optical, electrical, or mechanical properties. These coatings are composed of thin...

(TOF) The length of time needed for a signal to arrive at and be reflected from the target. The basis of an active autoranging/autofocus system.

In a cathode-ray tube, the visible line or lines formed on the screen by the deflection of the electron stream.

Pertaining to materials having the property of reflecting a part and transmitting a part of the incident radiation.

Measure of the amount of light that is transmitted, relative to the amount lost by absorption or reflection.

The distortion of an image formed by a cathode-ray tube, caused by unbalanced deflection voltages or deflection voltages that are not symmetrically aligned with the resultant anode potential.

Oscillator device composed of a semiconducting diode in a coaxial resonating cavity. When the biasing current is applied to the diode, high-frequency waves are emitted into the cavity where they are...

A color-television viewing system with three kinescopes, three lenses and three deflection yokes used to form the red, green and blue images required for a tricolor television projection.

Also known as corner-cube reflector or retrodirective reflector. Three reflecting surfaces, perpendicular to each other, that are arranged like the inside corner of a cube. As the triple mirror has a...

Computation of tristimulus values by integrating or summing, over the visible wavelength region, the product of the relative spectral power of a CIE standard source, the reflectance of the object...

A magnetic-deflection mass spectrometer that has an electrostatic field placed perpendicularly to its magnetic field, permitting both spatial mass dispersion and perfect double focusing in the plane...

The formation and display of three-dimensional images by ultrasonic energy. In one technique, the energy pulses from an ultrasonic transducer scan the object through a liquid medium and, receiving...

Ultraviolet (UV) fiber optics refers to optical fibers that are designed and optimized for the transmission of ultraviolet light, which is electromagnetic radiation with wavelengths shorter than...

Also known as UV-VIS spectrometer, a device that measures the absorbance, reflectance or transmittance of light in the ultraviolet or visible wavelengths absorbed, reflected or transmitted. Commonly...

A multilayer antireflective thin-film coating, so called because its reflectance rises steeply at wavelengths above and below a narrow band at zero. The v-coat is particularly useful in high-power...

A lens assembly containing several movable elements to permit changing of the effective focal length (EFL). Unlike a zoom lens, a variable-focus lens may require refocusing with each change of EFL....

A scanning technique in which the optical density of the film being scanned controls the speed of deflection of the scanning beam.

With respect to microscopy, light that is directed down through the objective onto the specimen and then returned by reflection.

A waveguide is a physical structure or device that is designed to confine and guide electromagnetic waves, such as radio waves, microwaves, or light waves. It is commonly used in communication...

A beamsplitting mirror that reflects as a function of wavelength.

Whispering gallery mode (WGM) refers to a phenomenon in wave physics, particularly in optics, where waves, such as light or sound waves, are trapped and circulate along the periphery of a curved...

A grazing incidence mirror telescope with concentric conic surfaces having a single common point: a paraboloid-hyperboloid combination with two internal reflections.

Two flat parallel electrodes that are vertically mounted alongside each other in a cathode-ray tube and produce horizontal deflection of the beam when a difference of potential is applied between...

The series of processes used to identify and evaluate crystal structure by using crystalline solids to diffract x-rays. In the Laue method, radiation of a wide range of wavelengths is transmitted by...

Fluid used to aid in examination of semifinished blanks.

A mirror that supplies equal reflectance for both the S-polarization and the P-polarization of a laser for a defined angle of incidence, usually 45°.

The removal of the zero-order component of the Fourier spectrum distribution of an object with a small, opaque absorber or reflector in the Fourier plane, to produce images that appear bright on a...