content_image/382886.jpg content_image/382885.jpg content_image/382884.jpg content_image/382883.jpg content_image/382882.jpg content_image/382881.jpg content_image/382880.jpg
For z-polarized contacts in parallel configuration, 

and in anti-parallel configuration 

For x-polarized contacts in parallel configuration, 

<img src='content_image/382886.jpg'>

<img src='content_image/382885.jpg'>

<img src='content_image/382884.jpg'>

and in anti-parallel configuration. 

<img src='content_image/382883.jpg'>

For y-polarized contacts in parallel configuration, 

<img src='content_image/382882.jpg'>

and in anti-parallel configuration. 

<img src='content_image/382881.jpg'>

Noting that tan φ ≈ − k$_{X}$/k$_{Y}$ and k 2 0 ≈ k 2 X + k 2 Y we can write, 

<img src='content_image/382880.jpg'>

