Cutting tool using one or more machined tool tips with diffractive features in a continuous or interrupted cut fast tool servo

A cutting tool assembly, comprising:

• a substantially cylindrical work piece mounted for rotational movement;
• a drive unit connected to the work piece for rotating the work piece;
• a tool post mounted on a track for movement substantially parallel to a surface of the work piece to be machined;
• an actuator mounted on the tool post, the actuator comprising:
• a main body having an aperture;
• a piezoelectric stack secured and preloaded in the main body aperture;
• a tool tip carrier connected to the piezoelectric stack;
• and
• a tool tip, having a plurality of diffractive features, mounted on the tool tip carrier,
• wherein the piezoelectric stack moves the tool tip in an x-direction substantially perpendicular to a surface of the work piece to be machined;
• and
• a controller, connected to the drive unit and the actuator, for controlling the movement of the work piece relative to the tool tip via the drive unit and for controlling the movement of the tool tip via the piezoelectric stack, wherein the controller via the piezoelectric stack moves the tool tip into and out of the surface of the work piece to be machined during cutting of the surface,
• wherein the tool tip is in continuous or discontinuous contact with the work piece during cutting of the work piece, wherein during at least a portion of the cutting the plurality of diffractive features on the tool tip are in contact with the work piece, and
• wherein a size and shape of the plurality of diffractive features, and a spacing between the plurality of diffractive features, are designed for an amount or degree of diffraction of light desired for an optical film made from the machined work piece,
• wherein the tool tip has two facets with at least one diffractive feature on each of the facets.