Abstract: In a laser processing method, a workpiece is set with respect to a jig having a laser passage hole and a relative position of the jig and the workpiece is determined so that the laser passage hole can face toward a target processing point on the workpiece. Then, laser light is irradiated on the target processing point through the laser passage hole while creating a stream of an inert gas flowing from a peripheral area of the target processing point toward the target processing point and flowing away from the workpiece through the laser passage hole.

Abstract: A preform for an optical element is provided which involves less amount of deformation of glass in molding, and readily improves lifetime of the mold. The present preform for molding an optical glass element 10 exhibits an almost circular shape having a predetermined diameter in top view, exhibits a flattened semicircular shape having a predetermined overall height in side view, has a concave face on the top surface such that the predetermined overall height is attained at approximately the central position of the aforementioned circular shape, and has a concave face so as to fit along the convex face of the top surface such that a space is provided on the bottom face. The under surface may be either a concave face or a convex face. Also, the top surface may be either a concave face or a convex face.

Abstract: A preform for an optical element is provided which involves less amount of deformation of glass in molding, and readily improves lifetime of the mold. The present preform for molding an optical glass element 10 exhibits an almost circular shape having a predetermined diameter in top view, exhibits a flattened semicircular shape having a predetermined overall height in side view, has a concave face on the top surface such that the predetermined overall height is attained at approximately the central position of the aforementioned circular shape, and has a concave face so as to fit along the convex face of the top surface such that a space is provided on the bottom face. The under surface may be either a concave face or a convex face. Also, the top surface may be either a concave face or a convex face.

Abstract: A preform for an optical element is provided which involves less amount of deformation of glass in molding, and readily improves lifetime of the mold. The present preform for molding an optical glass element 10 exhibits an almost circular shape having a predetermined diameter in top view, exhibits a flattened semicircular shape having a predetermined overall height in side view, has a concave face on the top surface such that the predetermined overall height is attained at approximately the central position of the aforementioned circular shape, and has a concave face so as to fit along the convex face of the top surface such that a space is provided on the bottom face. The under surface may be either a concave face or a convex face. Also, the top surface may be either a concave face or a convex face.

Abstract: In a laser processing method, a workpiece is set with respect to a jig having a laser passage hole and a relative position of the jig and the workpiece is determined so that the laser passage hole can face toward a target processing point on the workpiece. Then, laser light is irradiated on the target processing point through the laser passage hole while creating a stream of an inert gas flowing from a peripheral area of the target processing point toward the target processing point and flowing away from the workpiece through the laser passage hole.

Abstract: A preform manufacture apparatus is provided which can produce a preform at low cost. A preform manufacture apparatus 1 has a first mold 20 which receives molten glass, and a second mold 50 which receives a molten glass block moved from the first mold 20. The first mold 20 has a receiving surface 20A which receives molten glass, and is dividable into two or more of split dies 30 and 40 at the receiving surface 20A.

Abstract: A preform for an optical element is provided which involves less amount of deformation of glass in molding, and readily improves lifetime of the mold. The present preform for molding an optical glass element 10 exhibits an almost circular shape having a predetermined diameter in top view, exhibits a flattened semicircular shape having a predetermined overall height in side view, has a concave face on the top surface such that the predetermined overall height is attained at approximately the central position of the aforementioned circular shape, and has a concave face so as to fit along the convex face of the top surface such that a space is provided on the bottom face. The under surface may be either a concave face or a convex face. Also, the top surface may be either a concave face or a convex face.