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Author Topic: What problems do Solar magnetic storms cause to fibre optic cables?  (Read 3397 times)

Offline syhprum

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Although I would not expect to see any effect on the glass data cores I presume there are repeaters that have to be powered and would think there are problems here.
« Last Edit: 04/03/2011 20:49:20 by syhprum »


 

Offline Soul Surfer

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It is unlikely unless they are powered by long electrical cables and the electrical supply is not protected against voltage and current surges.  This of course is quite possible but most telephone equipment is protected against lightning strikes.
 

Offline syhprum

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I have been trying to find information as to the power consumption of the repeaters, all I can find is that up to 200 repeaters are used on some circuits and the current thru the cable is one amp.
the insulation is meant to stand plus or minus 12KV so each repeater could obtain 120W if everything was pushed to the limit but I very much doubt it is that high.
Any leads would be very welcome.
I think any voltages induced by Solar activity would be negligible compared to the normal operating voltages.
 

Online yor_on

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This seems a good book about fiber optics Fiber optic reference guide. Repeaters and amplifying devices, used to reinforce the fibers optic signals/'radiation' may be susceptible if carelessly insulated, maybe?

Ordinary light do not bend to magnetic fields, and if defined as light quanta, photons do not interact with other radiation. There are some ways though. "virtual particles may contribute to the summation as well; for example, two photons may interact indirectly through virtual electron-positron pairs. In fact, such photon-photon scattering, as well as electron-photon scattering, is meant to be one of the modes of operations of the planned particle accelerator, the International Linear Collider." And "from quantum electrodynamics it can be found that photons cannot couple directly to each other, since they carry no charge, but they can interact through higher-order processes. A photon can, within the bounds of the uncertainty principle, fluctuate into a charged fermion-antifermion pair, to either of which the other photon can couple. This fermion pair can be leptons or quarks. Thus, two-photon physics experiments can be used as ways to study the photon structure, or what is "inside" the photon. The photon fluctuates into a fermion-antifermion pair. Creation of a fermion-antifermion pair through the direct two-photon interaction. We distinguish three interaction processes:

Direct or pointlike: The photon couples directly to a quark inside the target photon. If a lepton-antilepton pair is created, this process involves only quantum electrodynamics (QED), but if a quark-antiquark pair is created, it involves both QED and perturbative quantum chromodynamics (QCD).

Single resolved: The quark pair of the target photon form a vector meson. The probing photon couples to a constituent of this meson.

Double resolved: Both target and probe photon have formed a vector meson. This results in an interaction between two hadrons. For the latter two cases, the scale of the interaction is such as the strong coupling constant is large. This is called Vector Meson Dominance (VMD) and has to be modeled in non-perturbative QCD" from Two photon physics.

"There are practical devices called "optical isolators" and "optical circulators" that affect light differently based on whether the light is going forward or backward. These are common in the optical fiber industry. These devices are very strange since usually light rays follow the same path whether going forward or backward. (reflection, refraction, polarization rotation etc) The principle used is called the Faraday Effect and is induced by magnets in a strongly birefringent crystal. The strong magnets induce a change in the polarization of light and then the light interacts with optical polarizers. The interesting and amazing thing is that even though this is a polarization effect, people have been clever enough to make devices that are polarization independent."

And.

"[NASA] Laser light reflected by mirrors but unbent by magnets

A: A magnet can bend the path of any moving charged particle. In fact, that’s how your TV screen displays a video picture. A magnet deflects a beam of electrons to create a video pattern on the screen. Light, however, has no charge and therefore its path is unaffected by a magnet. But, you mention a magnetic field, which includes changing fields. If it’s a changing field, things get more complicated. Any changing magnetic field generates a changing electric field and that produces an electromagnetic wave.


Electromagnetic (EM) waves cannot interact directly with light photons since photons have no charge. EM waves do not bend light, at least enough that we can measure. If radio waves, for example, bent light appreciably then a transmitting radio station would look blurry. But stations don’t go blurry. Actually, electromagnetic waves can bend light through an indirect, quantum effect—but to such a tiny degree that we cannot measure it. This quantum effect (called Delbrück scattering) "is a process where, for a short time, the photon disintegrates into an electron and positron pair," says Norbert Dragon, physicist at the Institute for Theoretical Physics in Hanover, Germany. The charged pair interacts with an EM wave and then recombines into the photon with a changed direction. Thus, the EM wave bends the light. "More probably the charged pair will annihilate into two or more photons—this process has been observed under extreme conditions—but, then, the light ray is not bent but rather split into several rays," says Dragon. "
« Last Edit: 06/03/2011 13:24:01 by yor_on »
 

Offline syhprum

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after much hunting I have found a value for the voltage induced in the cable by solar storms.

http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1989GeoRL..16.1145M&db_key=AST

As the normal power supply is up to plus or minus 12Kv the power supply units can easily adjust for the variation
 

Online yor_on

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Geophysics :)

I missed looking there, good job syhprum.
 

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