| 摘要 |
PURPOSE:To prevent occurrence of fluctuation of refractive index in the production of a quartz rod lens by the VAD process, by adjusting the position of burner for producing fine glass particles, the content of P2O5 in the soot, and the number of revolution of the starting parent material to each specified value. CONSTITUTION:A burner 3 for producing fine glass particles is arranged to just below a tip end 2 of a starting parent material 1, and the starting parent material 1 is revolved with 50-70rpm. Then, O2 and H2 are supplied to the burner 3 generating a flame toward the tip end of the starting parent material 1. At the same time, a raw material A for glass contg. SiCl4, POCl3, etc. is supplied to the inside of the flame. Thus, fine glass particles contg. 10-18pts.wt. P2O5 are formed and deposited to the starting parent material 1 to form a soot preform 4. By heat-treating the soot preform 4 thereafter, a quartz rod lens having superior transmitting characteristic for light signal, high heat resistance, and high resistance to radiant rays is obtd. |
