With two optical fibers arranged in a line, a simple translation sensor can be configured as in the image below. The output from the two detectors can be proportioned to determine the translational position of the input fiber.

Several companies have developed rotary and linear fiber optic position sensors to support applications such as fly-by-light.

These sensors attempt

(1) to eliminate electromagnetic interference susceptibility to improve safetyand
(2) to lower shielding needs to reduce weight