Patent ID: 7452490

Claim:
A method of fabricating an optical substrate from a machined master surface of a workpiece, the method comprising: forming a replica of the master surface; and transferring the replica of the master surface to an optical substrate; wherein the master surface is formed by: bringing a cutting tool into contact with an initial surface of the workpiece; for a cutting pass, i, causing relative movement between the cutting tool and the initial surface along a path; wherein the path is determined by processing a mathematical function defined over a segment, C, of a coordinate system and characterized by a parameter selected from the group consisting of amplitude, phase, and frequency; wherein causing relative movement between the cutting tool and the initial surface comprises: bandpass filtering a noise signal; providing the bandpass filtered noise signal to a function generator; and generating a randomly modulated mathematical function from the function generator; cutting the initial surface by moving the cutting tool along the path according to the randomly modulated mathematical function.