Investigation on the Effect of Underwater Acoustic Pressure on the Fundamental Mode of Hollow-Core Photonic Bandgap Fibers

Abstract

Recently, microstructured optical fibers have become the subject of extensive research as they can be employed in many civilian and military applications. One of the recent areas of research is to enhance the normalized responsivity (NR) to acoustic pressure of the optical fiber hydrophones by replacing the conventional single mode fibers (SMFs) with hollow-core photonic bandgap fibers (HC-PBFs). However, this needs further investigation. In order to fully understand the feasibility of using HC-PBFs as acoustic pressure sensors and in underwater communication systems, it is important to study their modal properties in this environment. In this paper, the finite element solver (FES) COMSOL Multiphysics is used to study the effect of underwater acoustic pressure on the effective refractive index ( eff ) of the fundamental mode and discuss its contribution to NR. Besides, we investigate, for the first time to our knowledge, the effect of underwater acoustic pressure on the effective area ( eff ) and the numerical aperture (NA) of the HC-PBF.

Design of optical fibre based highly sensitive acoustic sensor for underwater applications

“…The PCF based acoustic sensor was reported by Dnyandeo et al [11] to monitor low-frequency underwater acoustic signal using Mach-Zehnder interferometric approach. A study on the effect of underwater acoustic pressure on the effective refractive index of the fundamental mode propagating in HC-PCF was reported by Abdallah et al [12]. Photonic crystal based hydrophone using Fabry-Perot interferometric approach was reported for ocean acoustics [13].…”