Photonics Dictionary: F

The simultaneous collection of two or more signals at a single location. In a digital computer, it refers to the number of inputs that can be accommodated by a particular logic circuit.

The transfer of a part of a device's or circuit's output back to its input.

An amplifying device that returns a portion of its output to its input as a means of modifying the device's performance.

A system designed to control the output quantity of a device by returning a portion of its output signal to its input. This results in the manipulation of the input quantity so that the desired...

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 plate consisting of fused optical fibers with both surfaces ground and polished, and having the entrance surface curved to match the image curvature of the input lens system. The plate transmits to...

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

A form of image intensifier designed to amplify a weak fluoroscopic image. The image is received at an input phosphor screen, as opposed to the light-sensitive electrode emitter used in regular image...

Reflection losses incurred at input and output of optical elements because of the difference in refractive index between glass and the immersion medium.