Key-coded SMA fiber connectors prevent errors in multi-fiber systems


OMC, the pioneer in optoelectronics design & manufacture, announces a new family of key-coded SMA fibre optic connectors with “clockface” style multiple keyways in up to 50 different orientations as standard. Originally designed in response to a customer request for a keyed connector for a four-channel installation, the new family of key-coded SMA connectors overcomes installation errors by effectively engineering them out.

In a multi-channel system, the usual way of connecting each fibre optic cable to the correct transmitter or receiver on the PCB is to tag each cable with an ident sleeve and match them up based on an installation plan, but this method is by no means fool-proof, and time-consuming errors are quite easily made. Each variation of OMC’s new family of key-coded SMA housings and connectors have all the benefits of the SMA connector; robustness of design, simplicity of installation and a secure locking nut; but also features two keyways – one master keyway at the 12 o’clock position to fix the orientation, and a second keyway which can be in one of multiple other positions around the clock to fix the channel number. Using this key-coded system, it is impossible to connect the wrong fibre optic cable to the wrong transmitter or receiver device.  Connectors and device housings with custom keyway positions for greater numbers of channels are also possible on request should the application require it.

The key-coded system is available on OMC’s full range of SMA device housings, including its popular H22 PCB-mount housing (pictured), as well as its H1 turret-style receptacle and its proprietary Vertical SMA (VSMA) housing which occupies only 7mm x 8mm of board space. This new series of all-metal housings and connectors is precision-machined at OMC’s UK manufacturing facility, and the company can align and house its full range of multimode fibre-optic transmitter and receiver diodes into any of the key-coded housings.

As an additional benefit, the keyway system eliminates rotational variation in the SMA connector mating, further enhancing performance consistency and link reliability.

In addition, the multi-key system is precision-machined using OMC’s CNC sliding-head lathes using a highly innovative iterative program devised by the company. This program continually increments the angular separation between the two keyways automatically from one part to the next, then engraves the connector with a channel number unique to that angular separation. This means that a transmitter or receiver housing and device connector will only mate with each other if they have the same channel number, identified via the engraving. This unique and novel approach allows over 50 different unique pairings to be produced automatically by machine, providing consistency previously only achievable via painstaking and costly manual operations.

Widely recognised as one of the world’s leading manufacturers of industrial fibre optic systems, OMC’s connectors and housed fibre optic transmitters and receivers are produced primarily to all-metal designs and are used in industrial and other environments such as mass-transit systems, where longevity, reliability and durability is essential. For many demanding applications, such as MRI scanners, life-support equipment, power grid equipment and secure, interference-free communications for defence and banking systems, standard off-the-shelf fibre optic components cannot meet the necessary optical performance window.  OMC’s proprietary Active Alignment Technology optimises each device and is relied on by its wide-ranging global end customer base.