Prediction of unknown aspect ratio of a single mode trapezoidal index fiber using splice loss technique considering angular misalignment

We use the splice loss measurement technique in absence and presence of angular misalignment and report a simple and accurate method to predict the unknown aspect ratio of a supplied circular core trapezoidal index single mode fiber. We, first, propose to determine the spot size of the unknown fiber from splice between two such fibers with angular misalignment. Then using a known empirical relation of power transmission coefficient and a graphical technique, we employ this spot size in splice loss between a step index and trapezoidal index fiber in absence of angular misalignment to predict the unknown aspect ratio. The method should find wide use by system developers and system users.