Single point diamond machining uses an extremely sharp diamond cutting tool to machine extremely accurate surfaces.  Diamond tools can be used in especially made laths, fly cutters, boring machines, NC machines and other machine shop tools to generate complex surfaces.

References are given as (p xxx) which refer to page xxx in the book "Micromechanics and MEMS"

The photograph below shows a jig bore machine modified by Robert Jebens to machine accurate grooves for alignment of telecommunication optical fibers.  A single pole, double throw optical fiber switch was made that aligned one fiber to one of two output fibers with sub micron accuracy (p 237, R Jebens, W Trimmer, and J Walker). The white block at the bottom of the photograph is plastic.  Slightly to the right and above the block is the diamond tip ready to machine a groove in the plastic.

The above jig bore was used with a high precision air bearing to machine an insulating tube with a several millimeter inside diameter, and a two micron wall thickness.  The tube, coated with four gold electrodes, is shown below.  The tube is so fragile it undulates and crinkles when not supported (p 327 W Trimmer & R Jebens).