This is kind of obscure but maybe by chance someone knows.
In my optics lab we have an adapter for converting FC/PC connectors to FC/APC (or vice versa). Here is a picture of it. It is about 7 cm long, black, and is polarization-maintaining. I have asked around, even some lab alumni and members of other labs, and nobody seems to know who bought it or the manufacturer. There is no brand name or logo on it. I’ve checked out a lot of the big optics companies (Thorlabs, Newport, Melles Griot, etc) as well as some smaller fiber suppliers and haven’t found it anywhere.
Does anybody know who makes this?