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 indexneffof 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 areaAeffand the numerical aperture (NA) of the HC-PBF.
Highlights
Optical fiber hydrophone is a significant area of research
We study the response of the hollow-core photonic bandgap fibers (HC-PBFs) to acoustic pressure by coupling between the acoustic-solid interaction (ASI) and the electromagnetic waves (EMW) modules in the finite element solver (FES)
The FES COMSOL Multiphysics is used to study the effect of acoustic pressure on the fundamental mode of a HC-PBF, mainly on neff, Aeff, mode-field diameter (MFD), and numerical aperture (NA)
Summary
Optical fiber hydrophone is a significant area of research. For many years, researchers have shown the prospects of using the conventional SMF interferometric hydrophones as alternatives to the conventional sound navigation and ranging (SONAR) systems [1]. The effective area can be used to study the nonlinearities, mode-field diameter (MFD), confinement losses, bending losses, splicing losses, and numerical aperture (NA) of the optical fiber [9, 10]. For this reason, studying the effect of acoustic pressure on Aeff allows getting information and important relations about how the acoustic pressure affects other important quantities. The EMW module in the FES is used to calculate neff for undeformed HC-PBF; the coupled ASI and EMW modules are used to calculate neff for the deformed fiber This enables us to study and analyse the effect of acoustic pressure on neff, Aeff, the MFD, and NA of the investigated HC-PBF.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
