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

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.

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Model Analysis of Underwater Acoustic Sensing with Hollow-Core Photonic Bandgap Fiber

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.568-570.581 ◽

2014 ◽

Vol 568-570 ◽

pp. 581-589

Author(s):

Adel Abdallah ◽

Chao Zhu Zhang ◽

Zhi Zhong

Keyword(s):

Acoustic Pressure ◽

Photonic Bandgap ◽

Single Mode ◽

Single Mode Fiber ◽

Elastic Model ◽

Hollow Core ◽

Detection Range ◽

Acoustic Sensing ◽

Underwater Acoustic ◽

Photonic Bandgap Fiber

Recently, using hollow-core photonic bandgap fiber (HC-PBF) for underwater acoustic sensing has been tested experimentally. Besides its unique characteristics and advantages over conventional single mode fiber (SMF), it provides higher responsivity to acoustic pressure. A robust deep water ray tracing model for multipath acoustic signals propagation and the elastic model of HC-PBF are both required to study the effects of underwater enviroment on the propagating acoustic signal for sensing with HC-PBF hydrophones. The combination of the two models allows studying the frequency response, sensitivity, detection range, and maximum operating depth of the HC-PBF hydrophones. The models analysis and simulations show the considerations that must be taken into account for the design and field operation of the HC-PBF hydrophones. In this paper, a complete package to study, design, optimize, and analyze the simulation results of the interferometric HC-PBF hydrophones is proposed.

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Experimental Study on the Concept of Hollow-Core Photonic Bandgap Fiber Stethoscope

International Journal of Optics ◽

10.1155/2018/6576397 ◽

2018 ◽

Vol 2018 ◽

pp. 1-4

Author(s):

Adel Abdallah

Keyword(s):

Experimental Study ◽

Relative Phase ◽

Fiber Optic ◽

Photonic Bandgap ◽

Single Mode ◽

Hollow Core ◽

Photonic Bandgap Fiber ◽

Photonic Bandgap Fibers ◽

Relative Phase Shift ◽

Phase Generated Carrier

An experiment is proposed to show the feasibility of using hollow-core photonic bandgap fibers (HC-PBF) in the fiber-optic interferometric stethoscopes to generally improve the sensitivity and overcome the problems associated with the electronic stethoscopes. In the experiment, the HC-1550 is used as a measuring arm of an unbalanced Mach-Zehnder interferometer (MZI) and the conventional single-mode optical fiber (SMF) is used as an isolated reference arm. Detection and demodulation of the relative phase shift is performed passively using phase-generated carrier homodyne technique (PGC). The proposed results indicate the significance of using HC-PBFs in the future stethoscopes.

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