Fiber-optic accelerometer with hydrophone applications

Area of Science:

• Photonics and Sensor Technology
• Mechanical Engineering
• Acoustics

Background:

• Traditional accelerometers face limitations in remote sensing and harsh environments.
• Fiber-optic sensors offer advantages such as electromagnetic immunity and miniaturization.
• Developing sensitive and robust accelerometers is crucial for various monitoring applications.

Purpose of the Study:

• To design, fabricate, and test a fiber-optic linear accelerometer.
• To evaluate its performance for general acceleration sensing.
• To assess its suitability and sensitivity for underwater acoustic monitoring (hydrophone applications).

Main Methods:

• Fabrication of a linear accelerometer using a cantilevered multimode fiber.
• Utilizing intensity modulation caused by lateral fiber displacement.
• Testing the device's displacement sensitivity and hydrophone performance at 1 kHz.

Main Results:

• The fiber-optic accelerometer demonstrated a displacement sensitivity of 6.4 x 10(-13) m.
• The device achieved a sensitivity limit of 75 dB relative to 1 microPa at 1 kHz when used as a hydrophone.
• The sensor leverages inherent advantages of remote optical fiber sensing.

Conclusions:

• The developed fiber-optic linear accelerometer is a viable sensor for general acceleration measurements.
• The device shows significant potential for sono-buoy hydrophone applications.
• Further improvements to enhance hydrophone sensitivity are discussed and feasible.