Fiber-to-copper media converters, also known as fiber optic media converters, are network devices that bridge the gap between fiber optic cabling and traditional copper cabling in Ethernet networks. In real networks such as campuses, factories, metro POPs converters let you reuse existing switches and still run fiber for long distance, EMI immunity. Devices used in fiber optic communication systems for data transmission across optical fibers are known as optical transceivers, or fiber optic transceivers.