04.06.2013 Views

Surface magneto-plasmons in magnetic multilayers - Walther ...

Surface magneto-plasmons in magnetic multilayers - Walther ...

Surface magneto-plasmons in magnetic multilayers - Walther ...

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Section 2.3<br />

Reflectivity of surface <strong>plasmons</strong> 19<br />

E(z) = Re −ik(i) z z ik<br />

+ Le (i)<br />

z z<br />

≡ A(z) + B(z). (2.38)<br />

R and L are constants <strong>in</strong> each layer. A(z) represents the amplitude of the right-<br />

travell<strong>in</strong>g and B(z) the amplitude of the left-travell<strong>in</strong>g wave. Further, as shown <strong>in</strong><br />

0 1 2<br />

n 0<br />

A 0<br />

B 0<br />

A ’<br />

1<br />

B ’<br />

1<br />

n 1<br />

d<br />

A 1<br />

B 1<br />

Figure 2.7: Illustration of the matrix method after Yeh [43]. Ai represents the amplitude<br />

of a right-travell<strong>in</strong>g wave and Bi of a left-travell<strong>in</strong>g wave on the left side of the<br />

<strong>in</strong>terface ij. And A ′ j and B′ j are the amplitudes of a right- and a left-travell<strong>in</strong>g<br />

wave on the right side of the <strong>in</strong>terface ij. ni is the complex refractive <strong>in</strong>dex of<br />

the medium i.<br />

Fig. 2.7, it is not only differentiated between right- and left-travell<strong>in</strong>g waves but also<br />

between waves on the right (with prime) and left (without prim) side of a given<br />

<strong>in</strong>terface. Regard<strong>in</strong>g A (′)<br />

i<br />

by a matrix.<br />

<br />

Ai<br />

Bi<br />

and B(′)<br />

i<br />

<br />

= ˆ D −1<br />

i ˆ Dj<br />

n 2<br />

A ’<br />

2<br />

B ’<br />

2<br />

x<br />

as column vectors, the amplitudes are connected<br />

<br />

A ′ j<br />

B ′ j<br />

<br />

≡ ˆ Dij<br />

where the ˆ Di are the so-called dynamical matrices given by<br />

Di =<br />

⎧⎛<br />

⎝<br />

⎪⎨<br />

⎛<br />

1 1<br />

√ ε (i) cos θi − √ ε (i) cos θi<br />

√ ε (i) − √ ε (i)<br />

⎞<br />

⎞<br />

z<br />

<br />

A ′ jB ′ <br />

j , (2.39)<br />

⎠ for s-polarised light<br />

⎝<br />

⎪⎩<br />

cos θi cos θi<br />

⎠ for p-polarised light .<br />

(2.40)

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!