Optical fiber and method for making the same
AssigneeSumitomo Electric Industries, Ltd.
InventorsTakemi Hasegawa, Masashi Onishi, Eisuke Sasaoka, Masayuki Nishimura
Life of this patent
Estimating the term…
Abstract
An optical fiber has a section of the first kind having a chromatic dispersion not less than a given positive value x and a negative chromatic dispersion slope at a given wavelength and a section of the second kind has a chromatic dispersion not more than −x and a positive chromatic dispersion slope at the same wavelength. Another optical fiber has a chromatic dispersion higher than a positive value x and a negative chromatic dispersion slope at a given wavelength band.
Claims23
An optical fiber composed of:
- at least a section of the first kind having chromatic dispersion not less than a given positive value x and negative chromatic dispersion slope at a given wavelength;
- and
- at least a section of the second kind having chromatic dispersion not more than −x and positive chromatic dispersion slope at said given wavelength.
An optical fiber having chromatic dispersion not less than a positive value x and negative chromatic dispersion slope at a given wavelength.
A method of making an optical fiber having voids extending along the fiber axis, comprising the steps of:
- preparing the preform having a plurality of voids whose cross-sectional areas are uniform along its axis;
- and
- drawing the optical fiber from said preform, wherein a means to measure the area fraction of voids in the drawn optical fiber, a means to adjust the pressure in said voids of the preform and a means to feedback the measured area fraction of voids to adjusting means are included.
A method of making an optical fiber which contains a plurality of regions made of sub mediums whose refractive indices differ from those of main mediums constituting the optical fiber comprising the steps of:
- preparing a preform having a plurality of regions made of sub mediums whose cross-sectional areas are constant along the preform axis;
- and
- drawing the optical fiber from said preform, wherein a means to adjust the heating condition through varying at least one of the temperature of the drawing furnace for heating said preform and the time length for the fiber to pass the drawing furnace is included.
A method of making an optical fiber which contains a plurality of regions made of sub mediums having refractive indices different from those of main mediums constituting said core and the cladding, comprising steps of:
- injecting a medium whose refractive index is changeable on exposure to radiation into given regions of the optical fiber;
- and
- varying the refractive index of said injected medium along the fiber axis by exposing the fiber to radiation.
A method of making an optical fiber having a plurality of voids, comprising the step of:
- closing the voids by heating and fusing the drawn optical fiber selectively at a plurality of portions spaced apart along the fiber axis.
Dependencies are inferred from the claim text.