Patent ID: 9002162
Filing Date: 2015-04-07
Classification: C03B

Abstract:
1. Process for manufacture of optical fiber comprising: (a) heating an optical fiber preform to the softening temperature, and (b) drawing an optical fiber from the preform, the invention characterized in that the optical fiber preform is prepared by steps comprising: (i) forming by Isothermal RF Plasma Inside Deposition (IRFPID): a down-doped glass gladding layer on the inside of an IRFPID silica starting tube, wherein the IRFPID comprises: (ii) inserting a glass core rod into the IRFPID silica starting tube, (iii) collapsing the IRFPID silica starting tube onto the glass core rod to produce a first solid glass body having a core material and down-doped cladding material on the core material wherein the negative delta values for the down doped glass cladding layer are lower than −0.05%.