| 摘要 |
PROBLEM TO BE SOLVED: To obtain porous glass preform of the tapered part reduced with high sedimentation efficiency and no bubble formation by providing a burner- moving mechanism that enables individual burners to move along the circumferential direction of the porous preform. SOLUTION: Figure (a) gives its longitudinal section, while Figure (b) shows its plan view. This production apparatus is equipped with a chamber 1, target 2, a porous glass preform 3, the core part 4, the second burner for clad 5, the first burner for clad 6, the burner for core 7, the burner-moving mechanism 8 and an exhaustion tube. The burner-moving mechanism 8 is for allowing the burners set in the chamber to move in the circumferential direction of the porous glass preform, equipped with a rail in the same distance from the soot-accumulating center and a jig for fixing the burner is fixed onto the rail. The jig for fixing the burner is allowed to slide along the rail whereby the burner becomes possible to move in the circumferential direction of the burner. In the figure, three burners are spirally arranged in the chamber. |
