| 摘要 |
PURPOSE:To control the deposition of the glass powder having a larger grain diameter and to easily heat or cool a substrate by directing the gas injection port of a gas burner above horizontal and inclining the surface of the substrate to be coated with a film below vertical. CONSTITUTION:A disk of metallic silicon, quartz, etc., is prepared as a substrate 2. The substrate 2 is put on the periphery of a rotor 1, and the rotor 1 is rotated by a motor 7. The raw gas is then supplied to a gas burner 3, the flame of the burner 3 is injected obliquely upward, and the fine powder 4 of glass is formed in the flame. The fine powder 4 is deposited on the surface of the substrate 1 to form a film. Since the glass film is formed in this way, the glass powder having a larger grain diameter falls before reaching the substrate surface and is not deposited on the substrate surface. Besides, bubbles are not produced in a waveguide forming stage, nonuniformity in refractive index of the glass film is not caused, or the waveguide is not disordered. |
