# Microfiber Interferometric Sensor for Ultrasound Detection

## TL;DR

A new microfiber sensor detects ultrasound with high sensitivity and resolution, outperforming traditional fiber sensors.

## Contribution

A multi-mode microfiber interferometric sensor is introduced for ultrasound detection with improved sensitivity and resolution.

## Key findings

- Multi-mode microfiber sensors preserve ultrasonic waveforms and offer higher sensitivity than single-mode sensors.
- The sensor achieved a detection limit of 540 Pa and a 5 MHz bandwidth.
- Photoacoustic experiments showed 10 times higher resolution with the microfiber sensor.

## Abstract

By setting up ultrasonic fields in solid and liquid environments, the propagation characteristics of ultrasonic waves were investigated, and a sensing experiment device with related physical field settings was constructed. A comparison of results between multi-mode microfiber and single-mode fiber interferometric sensors found that the multi-mode microfiber maintains the original ultrasonic waveform output and has much higher sensitivity than the single-mode fiber sensor. The sensor in the paper had a detection limit of approximately 540 Pa and a bandwidth of approximately 5 MHz. The photoacoustic experiment with the microfiber ultrasound sensor had the highest resolution, which is about 10 times that of a single-mode fiber sensor. In summary, the multi-mode microfiber interferometric sensor was applied to ultrasonic detection.