US 12,392,684 B2
Multimode optical fiber core cane classification method
John Steele Abbott, III, Elmira, NY (US); Scott Robertson Bickham, Corning, NY (US); Amanda Lee Billings, Wilmington, NC (US); Ian David Cook, Wilmington, NC (US); and Simit Mayank Patel, Greensboro, NC (US)
Assigned to Corning Incorporated, Corning, NY (US)
Filed by CORNING INCORPORATED, Corning, NY (US)
Filed on Sep. 23, 2022, as Appl. No. 17/951,695.
Claims priority of provisional application 63/249,866, filed on Sep. 29, 2021.
Prior Publication US 2023/0094509 A1, Mar. 30, 2023
Int. Cl. G01M 11/02 (2006.01); B07C 5/342 (2006.01); C03B 37/018 (2006.01); C03B 37/025 (2006.01); C03B 37/027 (2006.01); G01M 11/00 (2006.01)
CPC G01M 11/0228 (2013.01) [B07C 5/342 (2013.01); C03B 37/018 (2013.01); C03B 37/0253 (2013.01); C03B 37/027 (2013.01); G01M 11/30 (2013.01); G05B 2219/33189 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of classifying a core cane for use in forming a multimode optical fiber, the method comprising:
determining a relative refractive index profile Δ(r) of the core cane;
fitting the relative refractive index profile Δ(r) to an alpha profile Δfit(r) defined by

OG Complex Work Unit Math
where Δo,fit is a relative refractive index at a longitudinal centerline of the core cane, αfit is a core shape parameter, and afit is an outer radius of the core cane;
generating a non-alpha residual profile Δdiff(r)=Δ(r)−Δfit(r) for the core cane;
computing one or more metrics from Δdiff(r), and
using the one or metrics in a classification of the core cane, the classification comprising a prediction of whether a bandwidth at a pre-determined wavelength of an optical fiber drawn from a preform comprising the core cane exceeds a pre-determined bandwidth at the pre-determined wavelength.