Air-blown fibre - Part 3

Air-blown fibre, as noted earlier, is blown through a microtube that is installed between the two endpoints.  Such microtubes may be connected using various connectors.  A simple example is one that provides a straight-through connection.  Here is an example.

To connect a tube it is simply pushed into the connector, which locks it in place.  The tube it should be connected to is inserted at the opposite side.

To release the tube again, the white ring at the edge of the connector is pushed inwards.

Air-blown fibre - Part 2

The air-blown fibre shown below has yet more secrets to reveal.

Now one can clearly see the eight cores (or eight fibres) in the single 'fibre'

Zoomed in a bit more matters become even more obvious.

Yet again we need our matchstick to get a sense of scale.

Perhaps the setup to take these pictures may be interesting to some readers.

In this case a Pentax K-5 (silver!) fitted with a Pentax Auto Bellows K and a Pentax DFA 100 f/2.8 manually stopped down to f/8 at an exposure time of about 15s was used.  Strange how the auto functions of years gone by become manual (if they are old enough).  The Auto Bellows can step down the lens, but no longer fire the shutter, because the shutter mechanism is triggered by an electrical contact.  I cannot use my latest DA lenses because they have no aperture ring to limit the degree of stopping down that will occur.  But I am digressing.  The next post will focus on networks again.

Air-blown fibre

Installing optical fibre can be a costly and difficult process.  One relatively recent option to ease the task is known as air-blown fibre.  Rather than installing expensive fibre, one installs tubes, which look like straws that are often bundled together.

Fibre is then blown through these tubes as required.  The tubes may be installed over hundreds of meters - even a few kilometers.  And fibre can be blown through the tubes at tens to hundreds of meters per second.  Initially more tubes can be installed than required and fibre could be blown through them when required.  And an obsolete fibre can be removed and replaced with a new one.

The next picture shows a fibre in one of the tubes.

When one shines a light through the fibre it becomes clear that it actually consists of several fibres (or cores).  The next picture contains the same fibre as above, but this time lighted from the other end.

Of course we need an image with a matchstick in it for a sense of scale.  The following picture not only includes the matchstick, but also shows the fibre above with its outer coating stripped away.

To take matters to the real world, the next picture was taken at the place in a network room where all the various parts of some big network come together.  Various pieces of optical fibre are visible.  In particular, note the microtubes (making loops!) through which fibre has been blown to other buildings.

50 micron optical fibre

Here is a 50μ optical fibre through which an ordinary laser pointer's light is conducted.  The fibre is a patch cable with SC connectors at both ends.  Here is the light emerging from the one end of the ST connector.  A matchstick has been included in the picture for a sense of scale.  The orange cladding of the patch cable is visible in the background.

When the laser at the other end is switched off, one gets an even better feeling for the diameter of the fibre.

TOSLINK

This picture demonstrates a TOSLINK optical fibre conducting light though multiple loops.  An ordinary laser pointer is aimed at the one end of the fibre (at the bottom right hand corner of the picture).  The light emerges at the other end (top left).

Here are the two TOSLINK connectors.  The matchstick between them provides a sense of scale.  The fibre has a diameter of about 1mm.