FAQ
Can light be made to move or chase along a side emitting optic?
With roped or braided multicore fiber and special process at the common end optics can be made to chase in both directions and display multiple colors at same time.
Will we always see a difference in brightness along an optic?
Not necessarily so. The human vision system appreciates illuminance grades in a logarithmic fashion and if the transition was smooth would be very difficult to actually notice the differnce.
If we observe an optic of, say 30 meters, from one end to the other along the optic it would not matter in which end is situated the illuminator: we would see the optic homogenously lit, although we know that it is not possible. If we were to look at the same optic sideways, from some distance, then we would notice the difference in luminance, because we could compare both ends.
The judicious use of illuminatiors, daisy chaining the optics, restrictiong the length of the fibers to that recommended by manufacturers, the control of the contrast and the angle of vision, are the tools needed for a successful installation.
Could the light along a side emitting optic be totally homogeneous?
Despite the assurances of some manufacturers, this is a total impossiblility because it would clash with the laws of physics, as we know them.
In order for an optic to display the same illuminance along a given length, it would have to be perfect:with no losses.
As soon as light is produced by an emitter starts to decay, in a similar fashion that a bullet starts to lose speed from the moment it issues from the muzzle of a gun.
The light is not the same inch by inch in an optic as it leaves the optical port of the illuminator: the farthest from the light source, less lith, due to the attenuation of the optic.
What are the design constraints to side emitting optics?
The actual illuminance of side emitting optics is low, although the luminance is quite acceptable in most cases. This means that if the contrast value are correctly applied the visibility of the optics can be excellent. The actual quantity of ambient illuminance, the colors of backgrounds, distance and line of vision are parameters to be carefully balanced, in order to obtain the best results.
With all the limitations, what are the uses of side emitting optics?
There is a common misconception about the quantity of light needed for a given task: more light is not necessarily better, and often is worse than the right amount with correct characteristics.
In many instances, small quantities of light to demarcate, decorate or accent are much better than a glaring neon-like line.
A good example that comes to mind is the uses in the theatre, cinemas and public buildings to line out corridors, aisles and emergency exits: in these instance the brightness of neon would simply not be acceptable. Coupled with the beauty of color change capabilities side emitting optics are value tool in the hands of the designer for outlining buildings, both externally and internally, pools, spas, cornices, gardens, and all kinds of architectural details.
Another point not to be forgotten is the total safety of fiber optics. There is no electricity in them. This means that in all those instances where high voltage neon simply cannot be contemplated because of danger, maintenance or fragility; side-emitting fibers can be the only sensible alternative.
Can side emitting optics be as bright or brighter than neon?
Fiber optics can be made to be brighter than neon but only for very short distance. We can think of a garden hose as an example: making tiny holes along can cause amount of water gushing out of the holes nearer the tap, and for a distance that will depend on the size of the holes. If we make the holes larger a greater amount of water will issue, but only for a shorter distance until it only trickles.
There is a limit to the quantity of water that can be made to pass through a hose, a limit given by the material of the pipe and viscosity of water. We simply cannot pressure infinitely.
The limit on the quantity of light traveling through a fiber optic is also imposed by physics:the actual material of which the optic is made and the intrinsic qualities of light. There is a power density limit to each material.
In some systems, especially with late generation purpose made metal halide illuminators, luminance values greater or equal to that of neon may be obtained for lengths up to few meters. The sizeable cost of these systems when compared to neon makes the proposal impractical in most cases.
Solid core or multicore?
The will depend on the use to which the optic is put and the actual installation conditions. Solid core optics have generally, a larger bending radius to avoid important losses. Furthermore, because of the transparent quality of the core, unless the contrast with the background is adequate the appearance is that inferior luminance.
Multicore optics, on the other hand, have a more flexible construction, especially in large diameter. Because of the reduced transparency of the optic, the luminance appears greater.
Solid core fibers can operate that are more powerful without damage to the core. It must be said, however, that the long-term effects, especially those related to the power denisty of the systems, are as yet undermined.
What are coiled roped and woven/knitted optics?
Simply braided or woven ropes manufactured with thin solid fiber optics, instead of hemp or nylon. Because of the strain produced on the individual fibers by mean of the torsion, coilding or knitting, the fibers have greater losses along the length. This means that more light is vailable for side viewing purposeds.
What are multistranded optic fibers?
Multistranded optic fibers are narrow walled tubes off transparent material, housing a number of smaller solid core fibers. The inner fibers are, generally 0.75mm in diameter and numbered from ten or less to several hundred, depending on the final use and diameter of the optic.
What are solid core fibers?
These optics are cylinders made of diverse polymers and encased on a transparent sheath or tube. As a standard are manufactured in different gauges or calibers from 3 to 25 or more millimeters in diameter.
Suggestions
The Hwaying Fiber Optic FAQ continues to expand and improve. If you have suggestions for improvement, we would enjoy hearing from you. Please contact us. Thank you!
