Photonics Dictionary: F

A laser oscillator in which two mirrors are separated by an amplifying medium with an inverted population, making a Fabry-Perot cavity. Standard diode lasers are Fabry-Perot lasers.

A femtosecond laser is a type of laser that emits ultrashort pulses of light with durations on the order of femtoseconds, where one femtosecond is equal to 10-15 seconds. These lasers are capable of...

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 fiber laser is a type of laser in which the active gain medium is an optical fiber doped with rare-earth ions such as erbium, ytterbium, or neodymium. Fiber lasers generate coherent light through...

A fiber optic preform is a cylindrical glass rod or tube used as the starting material for manufacturing optical fibers. It serves as the precursor from which optical fibers are drawn. The process of...

A pulsed dye laser in which the excitation is provided by means of a flashlamp. Output is tunable from 335 to 850 nm, with peak power up to 7000 kW.

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

Time elapsed during the radiant output change from 10 to 90 percent of maximum in a light-emitting diode or laser. Usually expressed in nanoseconds and measured from the moment of onset of the...

FMCW lidar stands for frequency-modulated continuous wave lidar. It is a type of lidar (light detection and ranging) technology used for remote sensing, distance measurement, and 3D mapping. FMCW...

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...

A frequency comb is a precise and regular series of equally spaced spectral lines, or frequencies, that are generated with great accuracy. The term "frequency comb" is often associated with the Nobel...

Fusion ignition refers to the point in a controlled nuclear fusion reaction where the energy released by the fusion reactions becomes self-sustaining, leading to a continuous release of energy...