of perfect conductors, where Oc -oo. Here both E-and H-fields inside the medium tend to zero, and the contributions of bound charges/currents become negligible. The effect of the radiation in this case will be the creation of a surface current density Js and a surface charge density or, both of which may be attributed in their entirety to the conduction electrons. The conservation of charge then requires that V J+dg/dt=0 3. Reflection of plane wave from a perfect conductor The material in this section is not new, but the line of reasoning and the methodology will be needed to build the necessary arguments in subsequent sections. The case of normal incidence on perfect conductors is well-known, but the two cases of oblique incidence, originally ublished in [10], have all but vanished from modern textbooks H (a) ++-+++-+++--+++ Js cose J Fig. 1. A linearly-polarized plane wave is reflected from a perfectly conducting mirror Whereas the parallel component of the E-field at the mirror surface is zero, the parallel nt of the H-field is at its maximum. The surface current J, is equal in magnitude cular in direction to the tic field at the surface. (a) Normal incidence que incidence with s-polarization. (c) oblique incidence with p-polarizatie In Fig. 1(a) a plane wave of wavelength no, having E-field amplitude Eo (units=V/m) and H-field amplitude Ho=EZ(units=A/m), where Z=vudEo-37722 is the free-space impedance, is incident on a perfect conductor. The Poynting vector is S=rEal(E xH") and the momentum density (per unit volume)is p=S/c(vacuum speed of light c= I/ueo In unit time, the incoming momentum over a unit area of the reflector is that contained Imn of base A= 1.0 m2 and height c. The same momentum returns to the source after ng reflected from the mirror, so the net rate of change of the field momentum over a unit #5025-S1500US Received 10 August 2004; revised 13 October 2004; accepted 20 October 2004 (C)2004OSA November 2004/Vol 12. No 22/OPTICS EXPRESS 5379of perfect conductors, where σc→ ∞. Here both E- and H-fields inside the medium tend to zero, and the contributions of bound charges/currents become negligible. The effect of the radiation in this case will be the creation of a surface current density Js and a surface charge density σ, both of which may be attributed in their entirety to the conduction electrons. The conservation of charge then requires that ∇ · Js + ∂σ /∂t = 0. 3. Reflection of plane wave from a perfect conductor The material in this section is not new, but the line of reasoning and the methodology will be needed to build the necessary arguments in subsequent sections. The case of normal incidence on perfect conductors is well-known, but the two cases of oblique incidence, originally published in [10], have all but vanished from modern textbooks. Fig. 1. A linearly-polarized plane wave is reflected from a perfectly conducting mirror. Whereas the parallel component of the E-field at the mirror surface is zero, the parallel component of the H-field is at its maximum. The surface current Js is equal in magnitude and perpendicular in direction to the magnetic field at the surface. (a) Normal incidence. (b) Oblique incidence with s-polarization. (c) Oblique incidence with p-polarization. In Fig. 1(a) a plane wave of wavelength λo, having E-field amplitude Eo (units = V/m) and H-field amplitude Ho = Eo/Zo (units = A/m), where Zo = √µo/εo ~ 377Ω is the free-space impedance, is incident on a perfect conductor. The Poynting vector is S = ½Real (E × H*), and the momentum density (per unit volume) is p = S/c 2 (vacuum speed of light c = 1/√µoεo). In unit time, the incoming momentum over a unit area of the reflector is that contained in a column of base A = 1.0 m2 and height c. The same momentum returns to the source after being reflected from the mirror, so the net rate of change of the field momentum over a unit H E Js H E Js cosθ θ θ (a) (b) H E Js θ θ +++ --- +++ --- +++ --- +++ (c) (C) 2004 OSA 1 November 2004 / Vol. 12, No. 22 / OPTICS EXPRESS 5379 #5025- $15.00 US Received 10 August 2004; revised 13 October 2004; accepted 20 October 2004