ACTIVE CORE ALIGNMENT
Alignment is the main factor, which contributes to insertion losses. How well two mating fibre cores align together will dictate how much light can transfer between them.

All the following tolerances effect alignment:

· Fibre diameter
· Connector hole diameter
· Core eccentricity
· Connector hole eccentricity

The Diamond connector series eliminates the effects of the first two factors by incorporating a 1st crimping stage. This stage closes the connector hole down onto the fibre so that they are a tight fit. This has the added benefit of ensuring an even distribution of epoxy around the fibre.

The last two parameters are eliminated by incorporating a 2nd crimping stage. This stage actively centres the fibre core by finding the centre point of the ferrule and moving the core to that point.

The resulting insertion losses achieved are less than 0.10dB. Although, other manufacturers can state 0.10dB for their product, this is only the case when their product is tested with a particular cable assembly. The result will not be achieved when mated with different assemblies, unlike the Diamond connections.

The two crimping processes are described in more detail below:
1st Crimping

· The circular V-edge of the crimping piston gently deforms the Cu-Ni alloy and reduces the hole diameter
  to the diameter of the fibre.
· The ferrule hole conforms to the diameter of the actual fibre diameter including fibre tolerances.
· The fibre is guided into the centre of the hole and uniform distribution of epoxy is ensured.
· At this point the eccentricity is approx. 1 micron.
2nd Crimping

· The second crimp actively aligns the fibre core on the ferrule axis.
· Light is injected into the fibre in order to illuminate the core. The ferrule is inserted into a high precision tungsten carbide sleeve
  and rotated, in order to detect if there is still and eccentricity between the fibre and ferrule axis.
· The 120° V-edge of the piston moves the fibre in 1/10 µm steps.
· After this operation the eccentricity is reduced to 0.25 µm max.
· The perfectly aligned fibre core results in consistently low insertion loss values when any two connectors are mated together.

Castlebar Technology Park,
Moneen, Castlebar, Co. Mayo, Ireland
Tel: +353 94 9027822 Fax: +353 94 9027811
E-Mail: info@fibrepulse.com