Splicing and termination — Fibre Optics Practice

Sample questions

1. 01What sets a splice apart from a pair of mated connectors?

   • AIt always loses more light than a mated connector pair
   • BIt is made to be unplugged and remade whenever it is needed
   • CIt joins two fibres for good, with less loss than a pair
   • DIt is only used to join fibres of different core sizes

   Why: A splice is a permanent joint between two fibres, with less loss than a connector pair, and it lives in a splice tray. Being made to unplug is what defines a connector, not a splice. The idea that a splice loses more than a connector is the wrong way round, and joining different fibre types is something to avoid, not the purpose of a splice.

2. 02In a fusion splice, what actually joins the two fibre ends?

   • AA crimp that presses both ends into a glass tube
   • BAn electric arc that melts the ends into one piece
   • CHeat from the sleeve oven that welds both ends together
   • DIndex-matching gel that sets between the two ends

   Why: A fusion splicer lines the fibres up and an electric arc melts them together into one piece of glass. Gel and crimped alignment tubes belong to mechanical splices. The oven is tempting because it is hot, but it only shrinks the protection sleeve over a splice that has already been made.

3. 03Which mechanical splice design copes with slight differences in fibre diameter?

   • AA V-groove splice that also takes ribbon
   • BA capillary splice with a fine glass tube
   • CAn elastomeric splice with soft grooves
   • DA clamp-on protector fitted over the joint

   Why: An elastomeric splice uses soft grooves that give a little, so they cope with slight differences in fibre diameter. A capillary splice relies on a glass tube with a bore just larger than the fibre, and a V-groove lays both fibres in one fixed groove, which suits single fibres and ribbons. A clamp-on protector covers a finished fusion splice and does not align anything.