Intensity-modulated optical-fibre vortex-shedding flowmeter

Optical-fibre intensity sensing of fluid flow rate is achieved using single-mode fibre tapers to detect the shedding frequency in a vortex-shedding flowmeter. Single-mode fibre tapers are characterized by their transmission versus bending at 1.3 μm and modelled using local normal modes and modal coupling techniques. A prototype vortex-shedding flowmeter is realized with the fibre taper acting as a secondary sensing strut.