| 摘要 |
<p>PURPOSE: A marking method and a marking apparatus, and a marked optical member thereby are provided to check the presence of a mark easily without using a specific reading apparatus, and to prevent breakage or lowering of strength of material by forming a diffraction grid in a deterioration range. CONSTITUTION: A marking object is prepared, and a laser beam(11) having a wave length range for transmitting the laser beam through a material forming the marking object is converged into the marking object. A multiple photon is absorbed, and the converging position of the laser beam is moved in the area, whose refractive index is changed due to the multiple photon absorption. In the change area of the refractive index, the converging position of the laser beam moves to form the diffraction pattern diffracting a visible light. The presence of the mark is detected without using a specific reading apparatus, and the strength deterioration of the object is prevented.</p> |
