Method of producing light-conducting glass structure

Claim 1

A METHOD FOR PRODUCING A GLASS FIBROUS STRUCTURE FOR CONDUCTING LIGHT ALONG THE CENTER AXIS THEREOF, CHARACTERIZED BY HAVING A REFRACTIVE INDEX DISTRIBUTION WITHIN SAID STRUCTURE WHEREIN A REFRACTIVE INDEX DECREASE CONTINUOUSLY IN A DIRECTION RADIALLY AND OUTWARDLY FROM SAID CENTER AXIS TOWARD THE OUTER SURFACE OF SAID STRUCTURE, SAID METHOD COMPRISING: PROVIDING A GLASS FIBER HAVING A CONSTANT REFRACTIVE INDEX AND A GENERALLY CIRCULAR CROSS-SECTION AND CONTAINING THEREIN A GLASS FORMING OXIDE AND A FIRST MONOVALENT CATION CONSTITUTING A GLASS MODIFYING OXIDE, CONTACTING SAID GLASS FIBER WITH A SOURCE OF SECOND MONOVALENT CATION ALL ALONG THE OUTER SURFACE OF THE GLASS FIBER AT A HIGH TEMPERATURE AND FOR A SPECIFIC TIME TO THEREBY CAUSE MIGRATION OF SAID FIRST TEMPERATURE TO THEREBY CAUSE INTERIOR OF SAID GLASS FIBER AT SAID TEMPERATURE TO THEREBY CAUSE SUBSTITUTION OF SAID SECOND CATION FOR SAID FIRST CATION IN THE GLASS OF SAID GLASS BIBER SO AS TO DECREASE THE REFRACTIVE INDEX OF THE GLASS FIBER IN A RADIALLY OUTWARD DIRECTION FROM SAID CENTER AXIS, AND CONTROLLING SAID SPECIFIC TIME IN SUCH A MANNER THAT SAID SECOND CATION IN SAID SOURCE MIGRATES INTO SAID GLASS FIBER THROUGH SAID OUTER SURFACE OF SAID GLASS FIBER TO THEREBY CAUSE SUBSTITUTION OF SAID SECOND CATION FOR SAID FIRST AND SECOND CATIONS WITHIN THE GLASS FIBER, SAID GRADIENTS CORRESPONDING RESPECTIVELY TO CONTINUOUS INCREASE AND DECREASE OF SAID FIRST AND SECOND CATIONS FROM SAID SURFACE TOWARD SAID CENTER AXIS OF SAID STRUCTURE TO THEREBY ESTABLISH SAID REFRACTIVE INDEX DISTRIBUTION BY SAID CONCENTRATION GRADIENTS OF SAID FIRST AND SECOND CATIONS.

Claim 2

A METHOD FOR PRODUCING A GLASS FIBROUS STRUCTURE FOR CONDUCTING LIGHT ALONG THE CENTER AXIS THEREOF, CHARACTERIZED BY HAVING A REFRACTIVE INDEX DISTRIBUTION WITHIN SAID STRUCTURE WHEREIN A REFRACTIVE INDEX DECREASE CONTINUOUSLY IN A DIRECTION RADIALLY AND OUTWARDLY FROM SAID CENTER AXIS TOWARD THE OUTER SURFACE OF SAID STRUCTURE, SAID METHOD COMPRISING: PROVIDING A GLASS FIBER HAVING A CONSTANT REFRACTIVE INDEX AND A GENERALLY CIRCULAR CROSS-SECTION AND CONTAINING THEREIN A GLASS FORMING OXIDE AND A FIRST MONOVALENT CATION CONSTITUTING A GLASS MODIFYING OXIDE, CONTACTING SAID GLASS FIBER WITH A SOURCE OF SECOND MONOVALENT CATION ALL ALONG THE OUTER SURFACE OF THE GLASS FIBER AT A HIGH TEMPERATURE AND FOR A SPECIFIC TIME TO THEREBY CAUSE MIGRATION OF SAID FIRST TEMPERATURE TO THEREBY CAUSE INTERIOR OF SAID GLASS FIBER AT SAID TEMPERATURE TO THEREBY CAUSE SUBSTITUTION OF SAID SECOND CATION FOR SAID FIRST CATION IN THE GLASS OF SAID GLASS BIBER SO AS TO DECREASE THE REFRACTIVE INDEX OF THE GLASS FIBER IN A RADIALLY OUTWARD DIRECTION FROM SAID CENTER AXIS, AND CONTROLLING SAID SPECIFIC TIME IN SUCH A MANNER THAT SAID SECOND CATION IN SAID SOURCE MIGRATES INTO SAID GLASS FIBER THROUGH SAID OUTER SURFACE OF SAID GLASS FIBER TO THEREBY CAUSE SUBSTITUTION OF SAID SECOND CATION FOR SAID FIRST AND SECOND CATIONS WITHIN THE GLASS FIBER, SAID GRADIENTS CORRESPONDING RESPECTIVELY TO CONTINUOUS INCREASE AND DECREASE OF SAID FIRST AND SECOND CATIONS FROM SAID SURFACE TOWARD SAID CENTER AXIS OF SAID STRUCTURE TO THEREBY ESTABLISH SAID REFRACTIVE INDEX DISTRIBUTION BY SAID CONCENTRATION GRADIENTS OF SAID FIRST AND SECOND CATIONS.

Claim 10

A METHOD FOR PRODUCING A GLASS FIBROUS STRUCTURE FOR CONDUCTING LIGHT ALONG THE CENTER AXIS THEREOF, CHARACTERIZED BY HAVING A REFRACTIVE INDEX DISTRIBUTION WITHIN SAID STRUCTURE WHEREIN THE REFRACTIVE INDEX DECREASE CONTINUOUSLY IN A DIRECTION REDIALLY ND OUTWARDLY FROM SAID CENTER AXIS TOWARD THE OUTER SURFACE OF SAID STRUCTURE, SAID METHOD COMPRISING: PROVIDING A GLASS FIBER HAVING A CONSTANT REFRACTIVE INDEX AND A GENERALLY CIRUCLAR CROSS-SECTION AND CONTAINING THEREIN A GLASS FORMING OXIDE AND A FIRST CATION CONSTITUTING A GLASS MODIFYING OXIDE, CONTACTING SAID GLASS FIBER WITH A GLASS CONTAINING SECOND CATION ALL ALONG THE OUTER SURFACE OF THE GLASS FIBER AT A HIGHER TEMPERATURE AND FOR A SPECIFIC TIME TO THEREBY CAUSE MIGRATION OF SAID FIRST AND SECOND CATIONS IN THE INTERIOR OF SAID GLASS FIBER AT SAID TEMPERATURE TO THEREBY CAUSE SUBSTITUTION OF SAID SECOND CATION FOR SAID FIRST CATION CONTAINED IN THE GLASS OF SAID GLASS FIBER SO AS TO DECREASE THE REFRACTIVE INDEX OF SAID GLASS FIBER IN A RADIALLY OUTWARD DIRECTION FROM SAID CENTER AXIS, SAID CONTRACTING BEING CARRIED OUT BY FUSING SAID GLASS ONTO THE SURFACE OF SAID GLASS FIBER, AND CONTROLLING SAID SPECIFIC TIME IN SUCH A MANNER THAT SAID SECOND CATION IN SAID SOURCE MIGRATES INTO SAID GLASS FIBER THROUGH SAID OUTER SURFACE OF THE GLASS FIBER TO THEREBY CAUSE SUBSTITUTION OF SAID SECOND CATION FOR SAID FIRST CATIONS SO AS TO FORM CONCENTRATION GRADIENTS OF SAID FIRST AND SECOND CATIONS WITHIN THE GLASS FIBER, SAID GRADIENTS CORRESPONDING RESPECTIVELY TO CONTINUOUS INCREASE AND DECREASE OF SAID FIRST AND SECOND CATIONS FROM SAID SURFACE TOWARD SAID CENTER AXIS OF SAID STRUCTURE TO THEREBY ESTABLISH SAID REFRACTIVE INDEX DISTRIBUTION BY SAID CONCENTRATION GRADIENTS OF SAID FIRST AND SECOND CATIONS.

Claim 11

A METHOD FOR PRODUCING A GLASS FIBROUS STRUCTURE FOR CONDUCTING LIGHT ALONG THE CENTER AXIS THEREOF, CHARACTERIZED BY HAVING A REFRACTIVE INDEX DISTRIBUTION WITHIN SAID STRUCTURE WHEREIN THE REFRACTIVE INDEX DECREASE CONTINUOUSLY IN A DIRECTION REDIALLY ND OUTWARDLY FROM SAID CENTER AXIS TOWARD THE OUTER SURFACE OF SAID STRUCTURE, SAID METHOD COMPRISING: PROVIDING A GLASS FIBER HAVING A CONSTANT REFRACTIVE INDEX AND A GENERALLY CIRUCLAR CROSS-SECTION AND CONTAINING THEREIN A GLASS FORMING OXIDE AND A FIRST CATION CONSTITUTING A GLASS MODIFYING OXIDE, CONTACTING SAID GLASS FIBER WITH A GLASS CONTAINING SECOND CATION ALL ALONG THE OUTER SURFACE OF THE GLASS FIBER AT A HIGHER TEMPERATURE AND FOR A SPECIFIC TIME TO THEREBY CAUSE MIGRATION OF SAID FIRST AND SECOND CATIONS IN THE INTERIOR OF SAID GLASS FIBER AT SAID TEMPERATURE TO THEREBY CAUSE SUBSTITUTION OF SAID SECOND CATION FOR SAID FIRST CATION CONTAINED IN THE GLASS OF SAID GLASS FIBER SO AS TO DECREASE THE REFRACTIVE INDEX OF SAID GLASS FIBER IN A RADIALLY OUTWARD DIRECTION FROM SAID CENTER AXIS, SAID CONTRACTING BEING CARRIED OUT BY FUSING SAID GLASS ONTO THE SURFACE OF SAID GLASS FIBER, AND CONTROLLING SAID SPECIFIC TIME IN SUCH A MANNER THAT SAID SECOND CATION IN SAID SOURCE MIGRATES INTO SAID GLASS FIBER THROUGH SAID OUTER SURFACE OF THE GLASS FIBER TO THEREBY CAUSE SUBSTITUTION OF SAID SECOND CATION FOR SAID FIRST CATIONS SO AS TO FORM CONCENTRATION GRADIENTS OF SAID FIRST AND SECOND CATIONS WITHIN THE GLASS FIBER, SAID GRADIENTS CORRESPONDING RESPECTIVELY TO CONTINUOUS INCREASE AND DECREASE OF SAID FIRST AND SECOND CATIONS FROM SAID SURFACE TOWARD SAID CENTER AXIS OF SAID STRUCTURE TO THEREBY ESTABLISH SAID REFRACTIVE INDEX DISTRIBUTION BY SAID CONCENTRATION GRADIENTS OF SAID FIRST AND SECOND CATIONS.

Claim 12

A method for producing a glass fibrous structure for conducting light along the center axis thereof, characterized by having a refractive index distribution within said structure wherein the refractive index decreases continuously in a direction radially and outwardly from said center axis toward the outer surface of said structure, said method comprising: providing a glass fiber having a constant refractive index and a generally circular cross-section and containing therein a glass forming oxide and a first cation constituting a glass modifying oxide; contacting said glass fiber with a source of a second cation all along the outer surface of the glass fiber at a high temperature and for a specific time to thereby cause migration of said first and second cations in the interior of said glass fiber at said temperature to thereby cause substitution of said seCond cation for said first cation in the glass of the glass fiber so as to decrease the refractive index of said glass fiber in a radially outward direction from said center axis; and controlling said specific time in such a manner that said second cation in said source migrates into said glass fiber through said outer surface of the glass fiber thus causing substitution of said second cation for said first cation to thereby form concentration gradients of said first and second cations within the glass fiber, said gradients corresponding respectively to continuous increase and decrease of said first and second cations from said surface toward said center axis of the structure to thereby establish said refractive index distribution by said concentration gradients of said first and second cations, said specific time being controlled so as to enable said second cation to reach at least said center axis to thereby cause decrease of the refractive index in a radial and outward direction and substantially in proportion to the square of the distance from the center axis at least in the vicinity of the center axis.

Claim 13

A method for producing a glass fibrous structure for conducting light along the center axis thereof, characterized by having a refractive index distribution within said structure wherein the refractive index decreases continuously in a direction radially and outwardly from said center axis toward the outer surface of said structure, said method comprising: providing a glass fiber having a constant refractive index and a generally circular cross-section and containing therein a glass forming oxide and a first cation constituting a glass modifying oxide; contacting said glass fiber with a source of a second cation all along the outer surface of the glass fiber at a high temperature and for a specific time to thereby cause migration of said first and second cations in the interior of said glass fiber at said temperature to thereby cause substitution of said seCond cation for said first cation in the glass of the glass fiber so as to decrease the refractive index of said glass fiber in a radially outward direction from said center axis; and controlling said specific time in such a manner that said second cation in said source migrates into said glass fiber through said outer surface of the glass fiber thus causing substitution of said second cation for said first cation to thereby form concentration gradients of said first and second cations within the glass fiber, said gradients corresponding respectively to continuous increase and decrease of said first and second cations from said surface toward said center axis of the structure to thereby establish said refractive index distribution by said concentration gradients of said first and second cations, said specific time being controlled so as to enable said second cation to reach at least said center axis to thereby cause decrease of the refractive index in a radial and outward direction and substantially in proportion to the square of the distance from the center axis at least in the vicinity of the center axis.