Fiber optic rotary joints (FORJ) are the optical equivalent of electrical slip rings. They enable uninterrupted transmission of an optical signal while rotating along the fiber axis. There are many different types of FORJs. Examples include a single-channel FORJ, multi-channel FORJ and hybrid FORJ. Single and dual channel FORJs are cost and size efficient. If more than two fibers are present in a system, multiplexing solutions are available which combine multiple channels onto one or two fibers and allow the use of one or two channel FORJs. Single channel fiber optical rotary joints have only one output channel for a single input channel where as multi channel FORJs can have more than one output channel for a single input channel. Hybrid FORJs have both optical and electrical channels. Other fiber optic rotary joints (FORJ) are commonly available.

There are several ways in which a fiber optic rotary joints (FORJ) functions. A singlemode fiber optical rotary joint uses singlemode fiber, which allows propagation of optical energy due to its small core and small numerical aperture. This results in high bandwidths of singlemode fiber. Due to low fiber attenuation, singlemode fiber systems operate at 1300 nm to 1550 nm wavelengths. A multimode fiber optical rotary joint uses multimode fiber which has large cores and large numerical apertures allowing multiple propagation of optical energy. Most multimode systems operate at 850 nm and 1300 nm due to high attenuation and dispersion. The features that should be considered when selecting a FORJ include its resistance to harsh environment, its size, and its configuration. Typically a fiber rotary joint is a part of a more comprehensive rotary interface. Custom fiber optical rotary joints are developed keeping user requirements in mind. Custom fiber optical rotary joints should provide optimum performance at a lower cost to the customer. A fiber optic rotary adapter allows fiber to rotate freely while maintaining uninterrupted transmission of an optical signal. Fiber optic rotary joints (FORJ) are designed and manufactured according to various industrial specifications.

Fiber optic rotary joints (FORJ) are used in many applications. Some examples include robotics, material handling systems, vehicle turrets, remotely operated vehicles, radar antennas, fiber optic cable reels, medical systems, video surveillance systems, security systems, marine propulsion systems, sensor platforms, and wind energy turbines. Fiber optic rotary joints (FORJ) have proven performance records in both industrial and military applications.