High-fidelity optical fiber microphone based on graphene oxide and Au nanocoating

Area of Science:

• Nanotechnology
• Acoustics
• Optical Engineering

Background:

• Traditional microphones face limitations in sensitivity and frequency response.
• The need for high-fidelity acoustic detection in diverse environments is growing.

Purpose of the Study:

• To demonstrate a high-fidelity optical fiber microphone (HF-OFM) with hybrid frequency and fast response.
• To enhance acoustic pressure detection sensitivity and improve microphone response flatness.

Main Methods:

• Utilized nanofabrication techniques involving a graphene oxide (GO) film, an Au nanocoating, and an air cavity.
• Employed mechanical tensile preparation to increase internal film stress and improve response flatness.
• Optimized the structural design of a 3nm Au nanocoating to enhance reflectivity and sensitivity.

Main Results:

• Achieved single, dual, and triple frequency acoustic signal detection from 0.1 kHz to 20 kHz.
• Demonstrated high acoustic pressure sensitivities (9.64-9.66 V/Pa) with a flat frequency response (<2 dB variation).
• Recorded a minimum detectable pressure (MDP) of 63.25 μPa/√Hz at 1 kHz and verified real-time audio transmission over a wide angular range (-90° to 90°).

Conclusions:

• The developed HF-OFM offers high sensitivity, a broad measurement range, and excellent frequency response.
• Its compact nature and performance make it suitable for oil leakage exploration, acoustic source localization, and real-time communication.