Photonics Dictionary: F

A polishing machine designed to permit adjustment of the polisher speed and motion for the control of flat surfaces.

A slab-shaped, very low profile package for electronic components; often used when printed circuit boards must be closely stacked together.

An electronic display in which a flat screen is formed by an orthogonal array of display devices, such as electroluminescent devices, light-emitting diodes or liquid crystal cells.

A frame taken with a CCD camera of a surface that is evenly illuminated by diffuse light. This frame shows irregularities in the light-sensing ability of the CCD, such as electronic defects and dust...

A lens that focuses on a flat plane because its field of curvature is close to zero.

An imaging device analogous to a drum scanner, but operating at greater speeds; it uses a row of sensors to traverse an image affixed to a flat surface.

A flexible display refers to a type of electronic visual display that is designed to be bendable, foldable, or rollable, allowing for unconventional form factors and enhanced portability. Unlike...

The fluctuation in apparent illumination that has a rate comparable to the reciprocal of the period of persistence in vision.

Any noise with a power spectral density that is the inverse of the signal's frequency and is therefore most significant for low-frequency signals. It can be expressed as 1/f and is therefore also...

A bench photometer that depends on the inability of the eye to distinguish color in brief flashes of light. Any difference in the intensity of reflected colored samples, presented to the observer in...

Heterochromatic photometry that depends on the elimination of chromatic flicker at a lower frequency than luminance flicker.

An instrument designed to give a visual indication to the pilot when the plane has strayed from a specific flight path.

One of the two major types of optical glass, the other being crown glass. Flint glass is softer than crown glass, has a higher dispersion and usually a higher refractive index.

An optical switch that controls conduction paths into and out of a junction in fiber optic and integrated optical circuits.

A reticle whose image may be moved about in a field of view.

A material that surrounds a fiber optic cable's buffer tubes to prevent moisture from entering if the jacket is breached.

An automatic camera that can record reduced images of documents at a rate of up to 30,000 documents per hour by having the film and documents move synchronously in opposite directions.

In various fields such as fluid dynamics, microfluidics, and biotechnology, a flow channel refers to a defined pathway through which a fluid (liquid or gas) flows. The channel can be of various...

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...

A flowmeter is a device used to measure the flow rate or quantity of a fluid passing through a particular point in a system. It works by sensing the velocity of the fluid passing through it and...

A technique developed to measure the molecular weight of macromolecules by analyzing the spontaneous fluctuations that occur in the inherent thermodynamic concentration of solute molecules in a...

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...

Optical glass that possesses a refractive index equal to or less than 1.5, and an Abbe number that ranges from 62 to about 85.

Fluorescein is a synthetic organic compound extensively used as a fluorescent tracer in various applications, particularly in medicine and biology. It belongs to the xanthene dye family and is known...

Fluorescence is a type of luminescence, which is the emission of light by a substance that has absorbed light or other electromagnetic radiation. Specifically, fluorescence involves the absorption of...

A powerful method, referred to as FCS, for determining the average diffusion coefficients of fluorescent molecules in solution or membranes. FCS measurements rely on recording the transition of...

A device, also called a fluorescence lifetime instrument, that measures decay curves of fluorescing samples. It generally consists of a gated pulsed flashlamp or a cavity dumped dye laser...

Fluorescence lifetime refers to the average time it takes for a fluorophore, a molecule that absorbs light at one wavelength and emits it at another, to return to its ground state after being excited...

Fluorescence lifetime imaging (FLIM) is an advanced imaging technique that provides information about the lifetime of fluorescence emissions from fluorophores within a sample. Unlike traditional...

Fluorescence microscopy is a specialized optical imaging technique used in biology, chemistry, and materials science to visualize and study specimens that exhibit fluorescence. Fluorescence is the...

The photographic recording of a subject that exhibits luminescence only for an extremely short time (10-8 s) after the exciting source is removed. In the process, the subject may be illuminated by...

The suppression of fluorescence by absorption of the stimulating radiation.

The spectroscopic study of radiation emitted by the process of fluorescence.

A tube containing mercury vapor and lined with a phosphor. When current is passed through the vapor the strong ultraviolet emission excites the phosphor, which emits visible light. The ultraviolet...

A type of optical microscope that allows the specimen being viewed to be irradiated by ultraviolet, violet and occasionally blue radiation, causing the specimen to fluoresce.

Fluorescent proteins are proteins that exhibit the property of fluorescence, which is the ability to absorb light at a specific wavelength and emit light at a longer wavelength. These proteins are...