An experimental study of micromachining step-mirrors for laser-diode beam shaping

Micro and ultra-precision machining is an effective approach to achieve the high-dimensional accuracy and surface finish required in optical and laser components. In this paper, an extensive study using a two-axis diamond turning machine is conducted to machine the step-mirrors used for laser-diode beam shaping. To position the workpiece precisely, theoretical analysis is made so that dimensional accuracy can be achieved. Investigations into machining burr reduction are carried out. With the process developed, step-mirrors with an optical surface finish of 8 nm in Ra and a minimized burr size of less than 0.5 µm are achieved.