Fiber Optic Plate/Element
From Night Vision Wiki
An FOP/FOE is an optical device made up of a bundle of a few millions to hundreds of millions of optical fibers with a diameter of several micrometers. These are usually concave in Image Intensifier Tubes.
An FOP/FOE is capable of transmitting an optical image from one surface to another without causing much image distortion.
Fiberoptic inverter
The most common type are fiberoptic inverters that invert the screen image by 180° compared to the one projected onto the photocathode mainly to make the optical system of monoculars and binoculars simpler.
