If you were slowing down light to make it green you'd need to start with ultra-violet light, not infrared.

The real physics is well documented on Wikipedia. I recommend reading their page on non-linear optics.

How it's going to finish is really straight-forward.

When the seven kingdoms have sufficiently weakened themselves via in-fighting, the Others will overwhelm the wall. Danerys lands on the shores of the seven kingdoms with her dragons. Jon Snow, who is clearly the prince-who-was-promised, joins forces with her to fight off the Others fulfilling the title of the series.

A handful of reasons off the top of my head:

EMR vendor support. (Or you could fly someone in ever time you needed help...)
Limited patient EMR access. (Web appointment scheduling, e-visits, medical record summaries, etc.)
Cross-deployment communication.
EMR internal messaging integration with external email accounts.
The dream of sharing medical records between organizations would also require this, but, alas, that's just a dream.