Model FO291


The FO291 is a multi-pass, singlemode fiber optic rotary joint (FORJ). It is passive and bidirectional, and allows the transfer of optical signals across a rotational interface on 2 to 9 separate singlemode optical fibers.

The FO291 can be combined with our electrical and / or fluid slip rings, giving a single, compact package for optical signals, electrical power and fluid transfer, with ISO 9000 quality.

Other options include fluid-filling for pressure compensation permitting operation at any ocean depth, and the combination of the model 190 to include up to a total of 19 multimode passes.

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  • 2 to 9 singlemode channels
  • Can be combined with our electrical slip rings, fluid rotary unions and the model 190 multimode fiber optic rotary joint
  • Alternative drive coupling arrangements are available (consult factory for specification details)
  • Tested to 10,000 psi (69,000 kPa) when fluid-filled
  • Aluminum and stainless steel construction
  • Connectorized interfaces, for easy fiber cable replacement
  • Rugged design
    • MIL-STD-167-1 ship vibration
    • MIL-STD-810 functional shock (40g)


  • Can be integrated into existing slip ring designs
  • Passive bidirectional optical transmission
  • Can be combined with our electrical slips and fluid unions
  • Long life

Typical Applications

  • Remotely operated vehicles
  • Floating production systems
  • Undersea telemetry
  • Seismic streamers
  • Radar antennas
  • Cable reels


Insertion Loss (dB) See Technical Data Sheet
Rotational Variation Typical < 1.0 dB, maximum < 2.0 dB
Back Reflection1 Typical > 22 dB, minimum > 18 dB
Wavelengths Suitable for operation over full CWDM band (18 wavelengths from 1271nm to 1611nm in 20nm increments), tested at 1310nm and/or 1550nm. Consult factory for other wavelengths such as 900-1100nm band (tested at 1060nm)
Rotational Speeds To 100 rpm dry and 60 rpm fluid filled. Consult factory for higher rotational speeds
Temperature -40° to +60° C standard. Consult factory for extended range
Exterior Surfaces Stainless steel and aluminum
Vibration Per MIL-STD-167-1A
Shock 40 g / 11 ms sawtooth per MIL-STD-810 Method 516
Connectors FC / PC connector bushings standard (ST connector bushings optional)
Pressure Up to 10,000 psi (69,000 kPa) for fluid filled version

1Lower back reflection available, consult factory



Technical Support

Telephone:  +1-902-468-2263