Q10.22Multiple choice
The optical properties of a medium are governed by the relative permitivity (εr ) and relative permeability (µr ). The refractive index is defined as µr εr = n. For ordinary material εr > 0 and µr > 0 and the positive sign is taken for the square root. In 1964, a Russian scientist V. Veselago postulated the existence of material with εr < 0 and µr < 0. Since then such ‘metamaterials’ have been produced in the laboratories and their optical properties studied. For such materials n = – µr εr . As light enters a medium of such refractive index the phases travel away from the direction of propagation.
- (i)According to the description above show that if rays of light enter such a medium from air (refractive index =1) at an angle θ in 2nd quadrant, them the refracted beam is in the 3rd quadrant.
- (ii)Prove that Snell’s law holds for such a medium.