Title:
アニール炉及び光学用合成石英ガラスの製造方法
Document Type and Number:
Japanese Patent JP4017863
Kind Code:
B2
Abstract:
An object of the present invention is to provide a method for producing an optical synthetic quartz glass, having a birefringence of lower than 0.5 nm/cm and having favorable refractive index distribution, yet without lowering the productivity, as well as to provide an annealing furnace suitably used in practicing said method. The method is characterized in steps of raising the temperature of a columnar optical synthetic quartz glass preform (G) to a temperature of from 800 DEG C to 1200 DEG C, and after keeping the temperature of the synthetic quartz glass preform in said range for a definite time, lowering the temperature; the temperature is lowered with a temperature difference of from 1 to 20 DEG C between the temperature of a light transmitting surface (E) of the optical synthetic quartz glass preform and the temperature of an outer peripheral side surface of the optical synthetic quartz glass preform with temperature-lowering rates of from 2 to 50 DEG C/hour, respectively.
Inventors:
Takayuki Oshima
Akira Fujinoki
Akira Fujinoki
Application Number:
JP2001384505A
Publication Date:
December 05, 2007
Filing Date:
December 18, 2001
Export Citation:
Assignee:
Shin-Etsu Quartz Products Co., Ltd.
International Classes:
C03B20/00; C03B19/14; G02B1/00; C03B32/00; C03C3/06
Domestic Patent References:
| JP6107421A | ||||
| JP5170466A | ||||
| JP2001220159A | ||||
| JP2001089170A |
Attorney, Agent or Firm:
Shoji Ishihara
Shinsuke Ishihara
Shinsuke Ishihara