Method of measuring distribution of internal reactive index for optical fiber preform and measuring device
AssigneesIssei Sasaki, Seiko EG&G Co., Ltd.
InventorIssei Sasaki
Life of this patent
Estimating the term…
Abstract
The internal refractive index distribution of an optical fiber preform is measured by providing a generally-cylindrical optical fiber preform having an uneven internal refractive index distribution. A picture image is placed at one side of the optical fiber preform, and a deflected picture of the picture image is photographed through the optical fiber preform using a photographing unit placed at the other side of the optical fiber preform. A deflection function is obtained by analyzing the deflected picture of the picture image. The internal refractive index distribution of the optical fiber preform is measured in accordance with the deflection function obtained.
Claims29
A method of measuring the internal refractive index distribution for an optical fiber preform, comprising the steps of:
- providing the optical fiber preform having an uneven internal refractive index distribution;
- locating a picture image at a first side of the optical fiber preform, the picture image having a preselected pattern containing position data;
- photographing a deflected picture of the picture image through the optical fiber preform using a photographing unit disposed at a second side of the optical fiber preform opposite the first side of the optical fiber preform;
- obtaining a deflection function by analyzing the deflected picture of the picture image by ray tracing the deflected picture of the picture image;
- and measuring the internal refractive index distribution of the optical fiber preform in accordance with the obtained deflection function.
A method of measuring the internal refractive index distribution for an optical fiber preform, comprising the steps of:
- providing the optical fiber preform having an uneven internal refractive index distribution;
- locating a picture image at a first side of the optical fiber preform, the picture image having a preselected pattern containing position data;
- lighting the picture image with an incoherent light source;
- photographing a deflected picture of the picture image through the optical fiber preform using a photographing unit disposed at a second side of the optical fiber preform opposite the first side of the optical fiber preform;
- obtaining a deflection function by analyzing the deflected picture of the picture image by ray tracing the deflected picture of the picture image;
- and measuring the internal refractive index distribution of the optical fiber preform in accordance with the obtained deflection function.
A measuring device for measuring the internal refractive index distribution of an optical tiber preform, the measuring device comprising:
- means for generating a picture image having a preselected pattern containing position data;
- an incoherent light source for lighting the picture image;
- a supporting unit for supporting the optical fiber preform having an uneven internal refractive index distribution;
- a photographing unit for photographing a deflected picture of said picture image through the optical fiber preform;
- and means for obtaining a deflection function from the photographed deflected picture by ray tracing the deflected picture of the picture image and for measuring the internal refractive index distribution of the optical fiber preform in accordance with the deflection function.
A measuring device for measuring the internal refractive index distribution of an optical fiber preform, the measuring device comprising:
- a supporting unit for supporting the optical fiber preform having an uneven internal reactive index distribution;
- means for locating a picture image at a first side of the optical fiber preform, the picture image having a preselected pattern containing position data;
- a photographing unit disposed at a second side of the optical fiber preform opposite the first side of the optical fiber preform for photographing a deflected picture of the picture image through the optical fiber preform;
- means for obtaining a deflection function from the photographed deflected picture;
- and
- means for measuring the internal refractive index distribution of the optical fiber preform in accordance with the deflection function.
Dependencies are inferred from the claim text.