Well, while I abandoned the project, I still have something to share.
First of all, I was busy studying my 3d printer. After realizing that the familiar SketchUp doesn't suit my needs, I switched to other CAD, and it happened to be FreeCAD.
FreeCAD is an open-source (LGPL) parametric geometry modeler, and it's super awesome because it's open-source. I've jumped in, and programmed support for Snell's law into its main 2D profile editor named Sketcher. That can seriously help with optics design. I'm very proud for that my Snell's law code was merged into main development branch of FreeCAD!
Also, I have set up some gear to aid me with infrared. The gear is just a power IR LED to light my bench, and a smartphone with a hacked camera that is able to see infrared (I just ripped IR cutoff filter off the camera).
With that setup, I made an important conclusion. All polarizers that I have (most are from LCDs, but also polarizing sunglasses and a photographic filter) are completely ineffective at near infrared (850 nm)! They just don't do anything, they are simply transparent. Surprizing, isn't it?
This means, I have to find some obscure polarizers that are specifically made for NIR, probably very expensive stuff. =(
Here are some pics made in infrared light. Some are out of focus, because I brke the focusing of smartphone's camera during surgery, and it is now fixed at focus distance of about 150 mm.