The Kerr Effect and Faraday rotation are DEFINITELY NOT arguments for interaction between electromagnetic fields and the propagation of light waves. For those interested in the details, read on.
The Kerr effect is an interaction between an electric field and a transparent medium. When the medium properties change due to the application of the field, this in turn affects how light is transmitted through the medium - the light itself is not interacting with the electric field. See: http://scienceworld.wolfram.com/physics/KerrEffect.html Similarly for Faraday rotation; the effect is to the medium through which light travels, not the light itself. In particular: "More than 150 years ago, Michael Faraday discovered that linearly polarized light traveling through a substance experiences a rotation when a magnetic field is applied to the material. The amount of rotation (R) was found to be proportional to the magnitude of the magnetic field (B) and to the length of the sample (l), R = V B l, where the constant of proportionality (V) is called the Verdet constant. A linearly polarized beam of light, one that has a unique E-vector direction, can be decomposed into two circularly polarized beams of equal intensity. These right- and left-circularly polarized beams propagate simultaneously but are independent of each other (orthogonal). An applied magnetic field causes the material to become optically active. This produces different refractive indices for the two beams, whereby they travel at different phase velocities. Thus when the two beams exit the material they have a different phase relationship, which is manifest in a rotation of the E-vector of the combined beams." From: Faraday Rotation Physics 1555 -- Waves and Optics Lab -- Winter 2002 D. Heiman, Northeastern University, 3/1/02 Ken Javor >From: "Michael Mertinooke" <[email protected]> >To: "Ken Javor" <[email protected]> >Subject: RE: Fiber optic cable testing per EN 55022:1998 ? >Date: Mon, Jan 13, 2003, 9:08 AM > > > Check out the Kerr Effect (aka "the quadratic electro-optic > effect") , and Faraday Rotation. Light can very definitely > be affected by electric and magnetic fields. > > Mike > >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]]On Behalf Of Ken Javor >> Sent: Friday, January 10, 2003 6:02 PM >> To: Peter L. Tarver; PSTC >> Subject: Re: Fiber optic cable testing per EN 55022:1998 ? >> >> >> >> I had forgotten the terminology, and what Mr. Tarver related about the >> classes is true, but it is not true that electric or magnetic >> fields should >> theoretically be able to interact with a stream of photons. >> >> ---------- >> >From: "Peter L. Tarver" <[email protected]> >> >To: "PSTC" <[email protected]> >> >Subject: RE: Fiber optic cable testing per EN 55022:1998 ? >> >Date: Fri, Jan 10, 2003, 3:53 PM >> > >> >> > >> > You're partially correct, Ken. However, the photon (in >> > quantum mechanics) is the particle that mediates the >> > electromagnetic force; photon also the name given to the >> > particle that is a quantum of electromagnetic energy. Thus, >> > photons are involved as the particle analog to an >> > electromagnetic wave. Also, an electron beam is not >> > identical to an electromagnetic wave in the sense you are >> > trying to characterize them. >> > >> > The primary difference between bosons (photons are bosons) >> > and fermions (which leptons are classified as; electrons are >> > leptons) is boson have integer spins, while fermions have >> > fractional spins (spin is a classification of "intrinsic >> > angular momentum") and bosons are not constrained by the >> > Pauli Exclusion Principle, whereas fermions are. >> > >> > This does not address why an electromagnetic wave of longer >> > wavelength may be redirected by the presence of an external >> > magnetic or electric field, while light is less affected. >> > >> > More properly, it is not an electron that creates an >> > electromagnetic wave, it's charge; electrons just happen to >> > possess a quantum of electric charge. An electric charge at >> > rest radiates an electric field. An electric charge in >> > motion creates a magnetic field, irrespective of >> > acceleration. >> > >> > Theoretically, it should be possible to magnetically or >> > electrically redirect light. >> > >> > By definition, light is visible and exists only between the >> > wavelengths of 700 nm-400 nm. "Light" and "optical >> > radiation" has been extended to other wavelengths (ir and >> > uv) in the common vernacular mostly because of "lasers" >> > being used at those wavelengths. >> > >> > >> > >> > Regards, >> > >> > Peter L. Tarver, PE >> > Product Safety Manager >> > Sanmina-SCI Homologation Services >> > [email protected] >> > >> > >> >> From: Ken Javor >> >> Sent: Friday, January 10, 2003 9:24 AM >> >> >> >> The answer is independent of frequency, it is the >> >> nature of the particle >> >> (electron vs. photon) that is key. I have >> >> forgotten the terminology, but >> >> one type of particle is called a boson, and per >> >> my (quite possibly faulty) >> >> recollection, bosons do not interact with >> >> electromagnetic fields. For >> >> example, you can use either an electric or >> >> magnetic field to deflect and >> >> point an electron beam, but you cannot do so with >> >> a beam of light. >> >> >> > >> > >> > ------------------------------------------- >> > This message is from the IEEE EMC Society Product Safety >> > Technical Committee emc-pstc discussion list. >> > >> > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ >> > >> > To cancel your subscription, send mail to: >> > [email protected] >> > with the single line: >> > unsubscribe emc-pstc >> > >> > For help, send mail to the list administrators: >> > Ron Pickard: [email protected] >> > Dave Heald: [email protected] >> > >> > For policy questions, send mail to: >> > Richard Nute: [email protected] >> > Jim Bacher: [email protected] >> > >> > All emc-pstc postings are archived and searchable on the web at: >> > http://ieeepstc.mindcruiser.com/ >> > Click on "browse" and then "emc-pstc mailing list" >> > >> >> ------------------------------------------- >> This message is from the IEEE EMC Society Product Safety >> Technical Committee emc-pstc discussion list. >> >> Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ >> >> To cancel your subscription, send mail to: >> [email protected] >> with the single line: >> unsubscribe emc-pstc >> >> For help, send mail to the list administrators: >> Ron Pickard: [email protected] >> Dave Heald: [email protected] >> >> For policy questions, send mail to: >> Richard Nute: [email protected] >> Jim Bacher: [email protected] >> >> All emc-pstc postings are archived and searchable on the web at: >> http://ieeepstc.mindcruiser.com/ >> Click on "browse" and then "emc-pstc mailing list" >> > This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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