Abstract: A method for sintering of a glass preform with reduced helium gas consumption and with reduced cost without affecting any optical or other parameter of the fiber obtained from glass preform processed in this way. The method includes a first step to perform dehydration of the glass preform inside a dehydration module, a second step to perform down-feeding of the glass preform inside a sintering furnace, a third step to perform sintering of the glass preform inside the sintering furnace, a fourth step to move the glass preform in upward motion, and a fifth step to perform re-sintering of the glass preform inside the sintering furnace. Also, the glass preform undergoes dehydration for time period in range of about 20 minutes to 120 minutes. Also, dehydration of the glass preform is performed in presence of helium gas.

Abstract: The present invention relates to an optical fiber (100) with a core (102) extending along a central axis (112), a cladding (104) surrounding the core. The core comprises a first up-dopant and a second up-dopant. And, the cladding comprises a first cladding (106) surrounding the core, a second cladding (108) surrounding the first cladding, and a third cladding (110) surrounding the second cladding. The first cladding has a second up-dopant, the second cladding has down-dopant, and the third cladding is undoped. Further, the first cladding (106) has traces of the first up-dopant and the down-dopant, the second cladding (108) has traces of the second up-dopant, and the third cladding (110) has traces of the down-dopant.

Abstract: The present invention relates to an optical fiber having a core extending parallelly along a central axis of the optical fiber, an inner cladding surrounding the core and an outer cladding surrounding the inner cladding. In particular, the core is up-doped with first and second up-dopants and the inner cladding is up-doped with the second up-dopant. Moreover, the outer cladding is un-doped. Further, the optical fiber has an attenuation of less than 0.2 at a wavelength of 1625 nanometres (nm), the attenuation of less than 0.18 at a wavelength of 1550 nm, or the attenuation of less than 0.32 at a wavelength of 1310 nm and a cable cutoff in a range of 1186 nanometres (nm) to 1194 nm.

Abstract: A method for sintering of a glass preform with reduced helium gas consumption and with reduced cost without affecting any optical or other parameter of the fiber obtained from glass preform processed in this way. The method includes a first step to perform dehydration of the glass preform inside a dehydration module, a second step to perform down-feeding of the glass preform inside a sintering furnace, a third step to perform sintering of the glass preform inside the sintering furnace, a fourth step to move the glass preform in upward motion, and a fifth step to perform re-sintering of the glass preform inside the sintering furnace. Also, the glass preform undergoes dehydration for time period in range of about 20 minutes to 120 minutes. Also, dehydration of the glass preform is performed in presence of helium gas.

Abstract: The present disclosure provides a method for sintering of an optical fiber preform. The method includes preheating of the optical fiber preform in a sintering chamber. In addition, the method includes first downfeeding of the optical fiber preform into a sintering furnace in the presence of helium gas and chlorine gas. The first downfeeding of the optical fiber preform facilitates sintering of an outer layer of the optical fiber preform. Further, the method includes pulling out the optical fiber preform from the sintering furnace in presence of chlorine gas and at least one of nitrogen gas and helium gas. Further, the method includes second down feeding of the optical fiber preform in the sintering furnace in the presence of nitrogen gas and chlorine gas. The second downfeeding of the optical fiber preform facilitates sintering of the optical fiber preform.