FORJ Fiber Optic Rotary Joints
November 16, 2018
Single Channel Multi-Channel Hybrid FORJ Fiber Optic Rotary Joints
Fiber Optic Rotary Joints (FORJs) are to optical signals what electrical slip rings are to electrical signals, a means to pass signals across rotating interfaces, particularly when transmitting large amounts of data. FORJs maintain the intrinsic advantages of fiber end to end.
Custom rotary joint slip rings are also available—Contact us to discuss your custom requirements.
Single or Multi-Channel
FORJs are available in single and multi-channel options. The most cost and size efficient options are the single and dual channel designs. If more than two fibers are present in a system, multiplexing solutions are available to combine multiple channels onto one or two fibers to allow the use of a one or two channel FORJ.
1.Single Channel FORJ
Our single channel (single-pass) FORJs are available with singlemode or multimode fibers. They are passive and bidirectional, and allows the transfer of optical signals across rotational interfaces.
When multiple fibers are needed, out Multi-channel FORJs are available with singlemode or multimode fibers. They are passive and bidirectional, and allows the transfer of optical signals across rotational interfaces.
Single mode or Multimode
Singlemode fibers allow the propagation of a single mode of optical energy due to their small core size and small numerical aperture and for this reason they exhibit very high bandwidths at wavelengths between 1270nm and 1650nm. Because of these smaller core sizes and numerical aperture, singlemode FORJs must be designed with very precise mechanical alignments. The alignment requirements are dependent on the operating wavelength of the FORJ. Standard singlemode FORJs are constructed for operation at 1310nm and 1550nm wavelengths. These FORJs can be expected to perform to the same specifications when used at other wavelengths between 1270nm and 1650nm, for instance, at coarse wavelength-division multiplexing (CWDM) wavelengths, which include 18 wavelengths of 1271nm to 1611nm in 20nm increments. FORJs can be tested at any or all CWDM wavelengths before shipment if desired in order to characterize performance at these wavelengths.
Multimode fibers have large cores and large numerical apertures allowing the propagation of multiple modes of optical energy. These features allow larger amounts of light to be transmitted from sources such as LEDs and VCSELs, but result in higher attenuation and dispersion. Because of these attenuation and dispersion features, multimode fiber systems are typically used for shorter datacom links. Most multimode systems operate at 850 nm and 1300 nm.
Hybrid FORJs combine an electrical slip ring with a fiber optic rotary joint, allowing electrical, power and optical signal transfer through a single rotational joint.
4.Complete Rotary Interfaces
Typically fiber optic rotary joints are part of a comprehensive rotary interface. JARCH has the experience to integrate other components for your assembly. It is common to incorporate other rotary components, such as slip rings, fluid rotary unions, resolvers, encoders, motors and actuators into advanced rotary interface assemblies.
- Ruggedized for harsh environments
- Compact sizes
- Variety of configuration options
- Custom designs available