Photonics Dictionary

The spectroscopic analysis of interference patterns using an electronic imaging tube with a Fabry-Perot interferometer to record the fringes.

The distribution of electromagnetic fields in a given area. The units are volts per meter, watts per meter squared and joules per meter cubed.

An electromagnon is a quasiparticle excitation that combines aspects of both magnetism and electric polarization in a crystal lattice. Specifically, it refers to a collective excitation of spins and...

A maser that relies on the fact that electrons in orbital motion in high-magnetic fields will emit energy at the cyclotron frequency. The transfer of energy is from the bunching of the electrons by...

An EMCCD (electron-multiplying charge-coupled device) camera is a type of scientific camera specifically designed for low-light imaging applications that require high sensitivity and fast readout...

An electron-beam lithography (EBL) system is a sophisticated nanofabrication tool used in the semiconductor industry and research laboratories to pattern extremely fine features with sub-micrometer...

A common form of high-precision, ceramic-based actuator capable of moving and measuring at the nanometer level.

Ellipsometry is an optical technique used to characterize the properties of thin films and surfaces. It is based on the measurement of changes in the polarization state of light reflected or...

The entrance slit, also known simply as the slit, is an essential component in optical instruments such as spectrometers and monochromators. It is a narrow opening or aperture through which light...

Epitaxial equipment refers to a set of specialized tools and systems used in the process of epitaxy, which is the growth of crystalline layers on a substrate material. Epitaxial growth is a critical...

1. The use of an electronic microdensitometer to measure points of equal density on a photographic deposit. 2. A technique that simplifies a picture's density pattern by making a single isodensity...

An Er:YAG laser is a type of solid-state laser that uses a crystal made of erbium-doped yttrium aluminum garnet (Er:Y3Al5O12) as the gain medium. The erbium (Er) ions are introduced into the crystal...

An etalon is an optical device that consists of two parallel reflecting surfaces separated by a precise and known distance. It operates based on the principle of optical interference and is used to...

Etaloning is an optical phenomenon that occurs in imaging systems, particularly in devices such as spectrometers, interferometers, and cameras. It is characterized by the appearance of interference...

Extreme ultraviolet (EUV) refers to a specific range of electromagnetic radiation in the ultraviolet part of the spectrum. EUV radiation has wavelengths between 10 and 124 nanometers, which...

Instruments used by ophthalmologists and optometrists to study the eye. There are, for instance, the ophthalmoscope to observe and photograph the retina; the retinoscope and optometer to determine...

The expression denoting the ratio of the equivalent focal length of a lens to the diameter of its entrance pupil.

An f-theta lens, also known as an f-theta scan lens or simply an f-theta lens system, is a specialized optical component used in laser scanning systems, particularly in laser marking, engraving, and...

A nonabsorbing, multireflecting device, similar in design to the Fabry-Perot interferometer, that serves as a multilayer, narrow-bandpass filter.

The series of rings when monochromatic light passes through a Fabry-Perot interferometer.

The spectroscopic analysis of interference patterns using a monochannel spectrometer, spectrograph or multichannel spectrometer with a Fabry-Perot interferometer to record the fringes.

A laser with output over a wide range of wavelengths spanning the far-infrared region of the spectrum (30 to 1000 µm); typically, it consists of a metal or dielectric waveguide one to two...

The signal-to-noise ratio (SNR) obtained with a Fourier transform spectrometer when detector noise prevails, which exceeds the SNR of a scanning spectrometer in the same time by a factor proportional...

A fiber Bragg grating (FBG) is a type of optical filter that is inscribed or "written" into the core of an optical fiber. It consists of a periodic modulation of the refractive index along the length...

A standard for fiber optic data transmission systems being developed by the American National Standards Institute (ANSI) and associated working groups that will make fiber optic components from...

A fiber optic cable assembly refers to a complete unit consisting of optical fibers, connectors, protective jackets, and other components that are assembled together to facilitate the transmission of...

A fiber optic gyroscope (FOG) is a type of gyroscope that uses the interference of light waves to detect changes in orientation or rotation. It operates based on the principle of the Sagnac effect,...

A fiber optic sensor is a device that uses optical fibers to detect and measure physical, chemical, biological, or environmental parameters. Unlike traditional electrical sensors, fiber optic sensors...

A coherent fiber optic bundle made from fibers whose diameter changes gradually along its length. Used to magnify or reduce the input image.

1. A lens situated at or near the plane of an internal image to project the aperture of a previous objective or erector upon the aperture of a following lens. 2. A lens at or near the plane of a...

A measuring eyepiece with a screw-micrometer-driven crosshair used to measure the size of the image.

An interferometer spectrometer designed to measure thicknesses of thin films or layers by recording the interferogram and by having a computer within the instrument to establish the distance between...

For a Fabry-Perot interferometer or etalon, a value for the transmission bandwidth which can be calculated as the ratio of the free spectral range to the full width half maximum of the transmission...

Fixed-pattern noise is the measure of the static (nontemporal) differences between pixels when the detector is evenly illuminated. In microbolometers, this effect is mostly caused by mismatch between...

Fizeau fringes are interference fringes observed in an interferometer, specifically in a Fizeau interferometer. The Fizeau interferometer is named after the French physicist Armand Fizeau, who...

The study of flames by means of a laser emitting blue light and a spectrometer to measure the green fluorescence created by the flame chemistry.

Flow chemistry, also known as continuous-flow chemistry, is a chemical manufacturing process where reactions take place in a continuous stream of fluids (liquids or gases) rather than in batch...

Flow cytometry is a powerful technique used in biology and medicine for the quantitative analysis of the physical and chemical characteristics of cells and particles suspended in a fluid. The method...

Fluence is a term used in various scientific and technical disciplines to describe the amount of something per unit area. The specific meaning of fluence can vary depending on the context in which it...

The focal length of a lens is the distance between the lens's optical center (or principal point) and the image sensor or film when the lens is focused at infinity. In simple terms, it is the...

A single-particle scattering technique in which an incident laser beam is tightly focused by means of lenses to yield a focal spot in the scattering material with a diameter on the order of the...

Förster resonance energy transfer (FRET) is a mechanism describing the transfer of energy between two closely spaced fluorescent molecules. This phenomenon is named after the German scientist...

The frequency space between consecutive transmission peaks in the transmission spectrum of a Fabry-Perot interferometer or etalon. The free-spectral range is inversely proportional to the distance...