Sound induced vibrations on multi-mode fiber

A 5.76-second piano rendition of the Inspector Gadget Theme with a sampling rate of 44.1 kHz, played 2 mm from the multi-mode fiber. High-speed infrared camera data, derived from sound sampled at 1.93 kHz, consists of 10,000 frames capturing vibrations on a multi-mode fiber. It includes 128*8 pixel data and can be monitored, played, and processed through MATLAB.

- In our experimental setup, a telecommunications laser operating at a wavelength of L=1550 nm serves as the primary light source. The acoustic element of the study involves a speaker with a maximum power output of 90 dBa, strategically positioned at a distance of 2 mm from a multi-mode fiber (Thorlabs FG105LCA). This fiber undergoes vibrational modulation induced by the sound waves emitted from the speaker.

As the speaker produces sound, the multi-mode fiber responds with corresponding vibrations, thereby inducing dynamic alterations in the speckle pattern within the optical system. To discern the frequencies inherent in the sound wave's interaction with the fiber, we employ a high-speed infrared camera (Goldeye-008) to capture sequential frames at the system's output. This orchestrated convergence of acoustic and optical elements enables a comprehensive examination of the frequency modulation imparted by the multi-mode fiber in response to the applied sound stimulus. -