The thing on the picture is my prototype rotating compensator for mid-infrared range. If you – at least remotely – understand what it is, then this blog might be interesting for you.

My name is Premysl Marsik and I build ellipsometers. I opened this blog to have some online space where I can post stuff. Stuff that never fits into paper, stuff that gets skipped-over in talks or stuff that exists in some physical or digital folder and is difficult to find, even for me.

But what really got me started, and also where the blog title Elusive Minus comes from, is the persistent sign confusion that comes with ellipsometry. In the first few posts I will want to introduce notation and conventions which I tend to use and explain why am I using it. With that I will try to track first few elusive minuses.