Bloch Wall Generator

[BEP]

http://physicsworld.com/cws/article/news/30762

"The laser pulse was circularly polarized, which means that it creates an intense but highly localized magnetic field"

'Naaaa... U can't create a magnetic field with light! What heresy!'

Nature is always a two-way street. We have gyroscopes that use laser light and magnetic fields. It is about time these folks found out it works the other way, too.

Bucha idjets they ur

[hansvonlieven]

Thank you very much BEP,

Obviously it is early days yet, but the fact that it can be done opens a whole new avenue of research. Fascinating stuff.

Thanks again for pointing it out to me.

Hans von Lieven

[BEP]

I was quite sure the magnetic could be affected by light. When I saw the light must have Faraday rotation it connected to Helmholtz's ad infinitum rule.

The part that intrigues me is the timing. Theoretical maximum speed of electronic control of the magnetic is 2ns? While this works in fs? 2ns the maximum usable expected switching speed of any future electronic device or.....

Does this then mean there IS a speed difference between the electromagnetic and light OR they are working in different frames?

If different frames then different closed systems. This takes me back to ad infinitum

[DreamThinkBuild]

 Thanks for the link. I'll try taking the magnet out and see what effect it has.

Here is some more info on using light to affect magnetic material.

"...Moreover, the effect of this ultrashort optical pulse on a magnetic system was found to be equivalent to the effect of a similarly short magnetic field pulse with strengths up to 1 T. Therefore, in contrast to the well-known magneto-optical Faraday effect, where the polarization of light is affected by magnetic order, these experiments demonstrate the feasibility of the inverse, opto-magnetic phenomenon: polarized light affects magnetic order via the inverse Faraday effect..."

Really neat stuff.

http://www.ru.nl/ssi/research_program/spin_and/photomagnetic/
http://www.ru.nl/ssi/research_program/spin_and/opto-magnetism/

On playing around with the 7.2volt Dremel with the magnet attached I found that if I spin it next to this fish pump coil with U-shaped ferrite core at 20krpm I get about 172 volts 3milliamps. A Computer transformer gave me about 24 volts 450uamps on primary. Got me thinking of how to convert the Dremel into a small battery powered turbo generator. At 300-600 rpm I barely get anything out of these coils.

[jkgulick]

@hansvonlieven

No, I don't think that you will get the same effect if you leave the magnet out.  I believe the effect occurs because the magnet's field is disrupted and then restored.  If there was no magnet, you should not get any significant current if  you are crossing at the midpoint of the coil.  If there is no magnet and you move away from the midpoint of the coil, there will be a flux imbalance which will translate into current, but the current will come at a price.

However, one might be able to achieve greater efficiencies by having the coil(s) on a soft iron core or laminated core, but still using a magnet or magnets.  Refer back to my first diagram, and imagine that the coils are on iron cores with a magnet between them.  Or, see my second diagram and imagine that the coil is on a soft iron core with magnets on either end.

This is important, I will repeat, "see my second diagram and imagine that the coil is on a soft iron core with magnets on either end."

I think that that may give the highest efficiency.  Larger rotor magnets will easily be able to warp the field of the iron core, and as they pass by, the magnets on the ends of the coil will reestablish the field, while the coil collects significant power fron the flux changes... all without any Lenz drag.