A fiber optic switch is a communication control device used in different applications across different sectors, but it is mostly known for optical fiber networking.
In computer networking and communications, a fiber optic switch refers to any piece of circuit switching equipment placed between fibers; hence, it refers not only to a networking switch used in fiber optic networking but also to a small device attached between lines in order to make light signals follow one path or another, like a selector switch.
Techopedia explains Fiber Optic Switch
In computer networking, a fiber optic switch is used to send and receive data transmissions as well as to determine where each data packet needs to go, much like a common networking switch. The advantage lies in the speed and bandwidth that is available to an optical fiber network. Reliability is also enhanced since light signals are not affected by interference from electromagnetic waves, so noise is not an issue with fiber optic technology.
Other types of fiber optic switches are literally switches, as in a light switch, which uses fiber optic cables to deliver signals instead of traditional copper wires. This is because some environments are corrosive or have so much electromagnetic interference that traditional copper or any kind of metal wiring is not suitable for transmitting signals.