Using DMD system to make circular gratings and arrays is based on the character of Space Light Modulation (SLM)
of DMD chip which can control the reflected lights based on the input figures' gray-scale. Firstly, circular gratings
are simulated in a computer with some simulation software programmed in VC. Then, the figures are inputted in the
DMD chip. With the character of SLM of DMD chip, the reflected lights can be controlled according to the circular
gratings' gray-scale. The circular gratings can be obtained after being developed, fixed and etched. Many contrast
experiments are carried out to confirm the technique parameters of circular gratings, as well as fabricate the two
levels, four levels and array of circular grating. By use of this method, we are capable of making low-cost but useful
circular gratings easily. Their levels and radii can be controlled, which will be suited for many optical systems.
Compared with scoring mechanically, lithography and e-beam etching, binary optical methods are more convenient,
efficient and low-cost.