Fibre optic joints – it is all done with lenses and mirrors

Citation

(2000), "Fibre optic joints – it is all done with lenses and mirrors", Sensor Review, Vol. 20 No. 4. https://doi.org/10.1108/sr.2000.08720daf.002

Fibre optic joints – it is all done with lenses and mirrors

Fibre optic joints – it is all done with lenses and mirrors

Keyword Fibre optics

IDM Electronics has introduced a range of fibre optic rotary joints (FORJ) designed to provide high bandwidth data transfer with low data rate errors. FORJ are needed whenever large amounts of data are required to pass through a rotational interface.

Fibre optic joints are completely passive, unaffected by EMI/RFI and do not generate any interference. These characteristics make them suitable for a wide variety of applications especially in difficult and hazardous areas including undersea telemetry, remotely operated vehicles, radar antennas, streamers and cable reels for military and commercial use.

The range includes standard FORJ products and hybrid packages that can combine fibre, electrical and fluid rotary joints. These can be designed to customers' individual requirements and can be packaged for harsh environments including underwater use.

They can also be supplied as explosion proof for use in hazardous environments and customers can specify the type and position of the connector and mechanical interfaces. The range of units covers single-mode for telecommunications use and multi-mode for data applications.

Fibre optic joints fulfil the mating requirements of a connector while allowing continuous rotation between the two bodies that are attached. Various techniques are employed to ensure that the signal is transmitted with the minimum of loss.

The simplest FORJ configuration is a single channel design. This can be achieved using coaxial, opposed fibres, terminated with lenses. A single channel FORJ is made by allowing one of the fibre to lens assemblies to rotate using a suitable bearing configuration, while the other remains stationary. The IDM range includes the Models 197, 228, and 145 for multi-mode and the Model 206 for single-mode applications.

The Model 214 uses a system of gears and mirrors mounted on glass plates to provide a compact, two-channel multi-mode product. For more complex multi-channel applications, the Model 190 operates on the principle of a magnetically-coupled mirror/gear train. Each channel of the modular design has a lens terminated fibre on the axis of rotation, reflected into a complementary lens to fibre assembly through a mirror.

Modules can be coupled together to make multi-channel devices and combined with signal and high voltage slip rings. The housing is designed with seals for optional factory oil filling for use in submerged applications.

IDM can supply a wide range of FORJ (see Plate 2) and can also combine the FORJ technology with conventional electrical slip rings for power transmission. Liquid or gas rotary unions can also be integrated into the design. In addition, IDM can also supply the encoding and decoding devices that are used to convert the electrical signals for transfer down the fibre. Interfaces are available for standard bus systems and video as required.

Plate 2 Fibre optic joints - it is all done with lenses and mirrors

All IDM fibre optic joints are fully tested prior to despatch to ensure compliance with specification. They have a comprehensive warranty and support is available globally thorough a network of agents. While there is a standard range of joints, IDM will be pleased to quote for individual requirements. Please call with details of your application.

For further information, please contact Alan Meredith, IDM Electronics Ltd, 30 Suttons Park Avenue, Suttons Business Park, Reading, Berkshire RG6 1AW, UK. Tel: +44 (0)118 966 6044; Fax: +44 (0)118 966 6524: E-mail: info@idmelectronics.co.uk