Here is something you can try to wrap your brain around. With a positive index of refraction the phase velocity of the light in the material is slower than in free space, but with a negative index of refraction the phase velocity is faster, so the phase velocity of light in this material may actually get to be larger than the speed of light. The reson this still works (though not actually true) is because the group velocity or the speed at which information is transfered is still slower than the speed of light. One interesting consequence of this is that you can actually make it so that your phase velocity propagates the opposite way as your information. Though it would take some work, and i can't see a real application to it other than some odd research work for some poor phd student.
Reader Comments (Page 1 of 1)
gabe @ May 3rd 2006 3:45AM
Here is something you can try to wrap your brain around. With a positive index of refraction the phase velocity of the light in the material is slower than in free space, but with a negative index of refraction the phase velocity is faster, so the phase velocity of light in this material may actually get to be larger than the speed of light. The reson this still works (though not actually true) is because the group velocity or the speed at which information is transfered is still slower than the speed of light. One interesting consequence of this is that you can actually make it so that your phase velocity propagates the opposite way as your information. Though it would take some work, and i can't see a real application to it other than some odd research work for some poor phd student.