Ultra-efficient in-core acoustic waves in suspended core fiber for high frequency fiber-optic ultrasonic devices

High frequency acoustic waves confined inside a suspended core fiber (SCF) are revealed by numerical simulations for the first time. A standard single mode optical fiber (SMF) is modelled to explain the current research limitations. The acoustic frequency response and energy concentrated in both fibers are evaluated from 50 to 56 MHz with the 3D finite element method. The simulated dispersion curves are compared to the Pochhammer–Chree solutions. The energy in the SCF core at the resonance of 52.84 MHz is approximately 16 times higher compared to the SMF, indicating a new route for the design and fabrication of fiber-based ultrasonic devices.