| 摘要 |
PURPOSE:To make high-grade surface smoothness attainable in particular, by making abrasive grains collide with the work surface of an optical element from a direction along the surface, and polishing a protruding part of the surface to be removed while irradiating a laser beam against it. CONSTITUTION:A laser beam 10 is irradiated on a protruding part 7 beyond the range of tolerance detected at work surface form measurement before polishing, and simultaneously abrasive fluid is spouted out of a nozzle 8 toward this protruding part 7, making abrasive grains collode with the said part 7. Here, the abrasive fluid will not cause any chemical change to a workpiece at a certain temperature of, for example, 15-40 deg.C, but if exceeding this temperature range, chemical change occurs, so that simultaneously with the protruding part 7 heated by laser beam irradiation, the ambient abrasive fluid is also heated, thus temperature on and around the protruding part locally goes up. With this temperature rise, only the protruding part grows larger in reactivity with the abrasive fluid and thereby it becomes weakened by reaction, and furthermore being also fragile by thermal expansion, thus it comes to be easily removed selectively by the collision abrasive grains. After polishing of proper time, the protruding part 7 is thus selectively removed.
|
