We propose and demonstrate a technique easy to fabricate and measure water depth based on selective mode excitation using single-multi-single (SMS) mode structure. The high extinction ratio has been achieved by equally exciting preselected modes of the multi-mode fibre (MMF) by optimizing the core offset at both the input/output splices of the SMS structure, and a wavelength shifting has been achieved by varying the ratio of major to minor axis of the MMF loop. A theoretical analysis of the observed behaviour is also presented showing an excellent agreement between the theoretical and experimental results.
@article{arxiv.1812.03809,
title = {Single-Multi-Single Fibre Optic Structure Based Water Depth Sensor},
author = {Garima Bawa and Krishnendu Dandapat and Gyanendra Kumar and Indrajeet Kumar and Saurabh Mani Tripathi},
journal= {arXiv preprint arXiv:1812.03809},
year = {2018}
}