A novel technique for the measurement of index-profile in optical fiber preforms

摘要

A novel technique for the measurement of refractive-index profiles in optical fiber preform is presented. The method uses image distortion analysis with graphic data processing technique applying for determining ray deflection, which the index profiles can be numerically converted from. An object is located behind of the sample preform to observe its image and the image will be distorted if non-uniformity exists in the sample. In order to confirm the principle by experiment, we construct prototype system and try measurements by using usual GI and high NA performs, which have been out of the range of conventional perform analyzer. The result for usual GI preform shows a good agreement to the result obtained from fiber drawn from the preform and high NA index profile is also successfully measured with good accuracy.