| 摘要 |
PURPOSE:To manufacture an oxide powder rod for a core having a uniform refractive index distribution and a large coefft. alpha of distribution by specifying the crossing angles of burners for forming powder for deposition in the axial direction of a depositing member and powder for deposition in the pripheral direction to the axial line of the member in a vapor axial deposition method. CONSTITUTION:An oxide powder rod 7 for the core of an SI type optical fiber is manufactured by a vapor axial deposition method. At this time, the crossing angle theta1 between the axial line L of a powder depositing member 4 and the center line O1 of a burner 5 for forming powder for deposition in the axial direction of the member 4 is set to 0 deg.<=theta1<=45 deg., and a burner 6 for forming powder for deposition in the peripheral direction is placed so that the crossing angle theta2 between the line L and the center line O2 of the burner 6 is made 45 deg.<=theta2<=90 deg.. While rotating the member 4 in a reactor 1, prescribed gaseous starting materials, combustion gases and inert gas are spouted from both the burners 5, 6. Oxide powder is formed by flame hydrolysis using the combustion gases, and the powder is deposited on the tip of the member 4. By raising the member 4 in accordance with the deposition speed of powder, a powder rod 7 is manufactured. |
