Method for modification of surface of optical fiber preform

A method for modification of surface of an initial optical fiber preform, the method comprising:

• treating the surface of the initial optical fiber preform with 50-70 liters of chlorine per square meter of the surface of the initial optical fiber preform, wherein the surface of the initial optical fiber preform is treated with chlorine for modification of structure of silica cladding of the initial optical fiber preform by removing impure particles from the initial optical fiber preform;
• and
• performing flame polishing on the surface of the initial optical fiber preform subsequently after chlorination, wherein the flame polishing is performed to convert the initial optical fiber preform into a modified optical fiber preform, wherein the modified optical fiber preform is free from metallic impurities and the impure particles, wherein the modified optical fiber preform has a smooth surface with elevated long length tensile strength, wherein the modified optical fiber preform has reduced proof test breaks.

A method for modification of surface of an initial optical fiber preform, the method comprising:

• treating the surface of the initial optical fiber preform with 50-70 liters of chlorine per square meter of the surface of the initial optical fiber preform, wherein the surface of the initial optical fiber preform is treated with chlorine for modification of structure of silica cladding of the initial optical fiber preform by removing impure particles from the initial optical fiber preform;
• and
• performing flame polishing on the surface of the initial optical fiber preform subsequently after chlorination, wherein the flame polishing is to convert the initial optical fiber preform into a modified optical fiber preform, wherein the modified optical fiber preform is free from metallic impurities and the impure particles, wherein the modified optical fiber preform has a smooth surface with elevated long length tensile strength, wherein the modified optical fiber preform has reduced proof test breaks, wherein the flame polishing is performed at a temperature in a range of 1000−1400° C.