I worked a a company that made wavelength selectable fiber optic switch. The light was passed through a lense at different angles to create the various wavelengths that hit the mems (a couple dozen detectors each representing the different wavelengths). They used a server controllers to angle the lense and if you put too much jucie to the servo the lense would slam to one side causing it to jam making the switch worthless; except the scrap price of gold coated box of course. Think Fread Flinstone compared to what BB has now.