Abstract

The application of the focusing method to measure the refractive-index profiles of single-mode optical fibers and preforms is described. In this automatic and nondestructive technique, the fiber or preform is immersed in index-matching oil, and collimated light is passed transversely through it. The intensity distribution of the transmitted light is detected with a video camera and processed with the aid of a computer-controlled video analysis system that provides the profile within a few minutes. The profiles of boron-doped and germanium-doped fibers and preforms with maximum Δn varying from 0.0006 to 0.012 were measured with a repeatability of better than 1% and with a resolution better than 1 μm. The profiles of the preforms are in good agreement with those of the fibers and also with those of slab samples taken from the tips of the same preforms.

© 1979 Optical Society of America

Preform index profiling (PIP)

H. M. Presby and D. Marcuse
Appl. Opt. 18(5) 671-677 (1979)

Focusing method for nondestructive measurement of optical fiber index profiles

D. Marcuse and H. M. Presby
Appl. Opt. 18(1) 14-22 (1979)

Fluorescence profiling of single-mode optical fiber preforms

Herman M. Presby
Appl. Opt. 20(3) 446-450 (1981)

Refractive-index profiling of preform rods by a photoelastic method: application to VAD single-mode fiber preforms

N. Shibata, Masao Kawachi, and Takao Edahiro
Appl. Opt. 21(19) 3507-3510 (1982)

Measurement of refractive-index profile and transmission characteristics of a single-mode optical fiber from its exit-radiation pattern

Kazuo Hotate and Takanori Okoshi
Appl. Opt. 18(19) 3265-3271 (1979)