Interferometer designs for DRO or servo control?

Out of curiosity, has/is anyone making use of interferometry for sensing position?

I was browsing Lindsay Pub's reprint of "Precision lead screws, gears, and Pantographs - Machinery's Industrial Secretes" and see pictures of setup to measure lead screw quality using interferometer setups that remind me of the kinds of physics lab experiments we were doing in high school and college in the 60s.

I'm sure that there are widgets that use interferometry internally, but I'm thinking more in terms of DIY.