New technology of ballonet tool for polishing

A new optical fabrication technology of ballonet tool polishing is introduced. The ballonet is a bulbous flexible membrane covered with a polishing pad and pressurized by an internal fluid. The tool has several independently controlled variables which are the internal pressure, the polishing contact area, the precession motion and the rotation speed of the tool. According to the IRP-200 polishing machine tool, the principle and practical effect of ballonet polishing is described. It is showed by the research and experiment that ballonet tool polishing is a practical and economical polishing technology of high precision and possibly becomes a main direction of optical figuring development.