Patent ID: 11788927

Abstract:
A method for determining the refractive index profile of a preform when the RIP is not substantially step-index like. (a) The preform deflection function is measured and transformed into a measured RIP. (b) A RI level and radius are assumed for the preform layer being evaluated and a compensation level RIP is calculated. (c) A theoretical deflection function is generated corresponding to the assumed RI level and radius and the generated data are transformed into a fitting RIP. (d) The fitting RIP is compared to the measured RIP and the comparison is evaluated against a predetermined accuracy level for the preform layer being evaluated. (e) Steps (b) and (c) are repeated iteratively until the predetermined accuracy level has been achieved. Steps (b) through (e) are repeated for each preform layer that needs to be compensated. Finally, a measurement artifact compensated refractive index profile is calculated for the preform.