For the past fortnight swarms of fluoro-clad cacophonists have been eviscerating the streets of South Hobart to lay optic fibre cable for the National Broadband Network. Last week I caused the crew some amusement when I stopped to ask what the inside of the cable looks like. Apparently I’m the only person who’s shown the slightest bit of interest in their activities and I think they enjoyed having an audience for a brief while! They even gave me a short off-cut to take home and dissect. So here’s your chance to get up close and personal with your local optic fibre cable.

The thick plastic cladding that encloses optic fibre cable is peeled back to reveal a helix of coloured plastic tubes that contain the optic fibres.
Peeling back the thick plastic cladding that encloses optic fibre cable.

Peeling back the very thick protective coating reveals a helical arrangement of plastic tubes covered in a sticky, water-repellent gel. Each tube contains 12 very thin, very pliable (they feel like plastic) fibres coated in even more sticky gel. The fibres themselves come in a gorgeous palette of translucent colours, so whilst the cable doesn’t offer any opportunities for basket weaving, there’s plenty to dazzle my magpie’s eye.

So, what exactly is an optic fibre?

Here’s a brief description from the NBN’s own site:

Optic fibre is a thin glass or plastic strand that carries light along its length. Light from lasers is shone down the fibre and detected by a receiver at the other end of the fibre. Optic fibre is capable of transmitting information at a very high rate over very long distances … much faster than copper or wireless technologies

Department of Broadband, Communications and the Digital Economy

If you’re on the edge of your seat and want to know more then I suggest you read How does a fiber optic cable work? for a fascinating and simple explanation of how the light is actually transmitted along the cable. If you want to go even more in-depth then try How Fiber Optics Work, also by the brainiacs at How Stuff Works.