A FORJ – (Fibre Optic Rotary Joint) is the optical equivalent of an electrical contact ring, commonly called a Slip Ring. It provides uninterrupted transmission of an optical signal during rotation along the axis of the fibre. Also known as optical rotary connectors or optical slip rings, FORJ applications have proliferated with. Fiber optic slip rings, also known as fiber optic rotary joints or fiber optic rotary couplers, are devices that allow the transmission of light signals through an optical fiber while allowing the fiber to rotate. Fiber can be divided into: single-mode fiber and multimode fiber. A Metro ring refers to a fiber ring that covers a metropolitan area, connecting multiple locations such as data centers, offices, and.