MEMS-Based Reflective Intensity-Modulated Fiber-Optic Sensor for Pressure Measurements

Area of Science:

• Optoelectronics
• Sensor Technology
• Microelectromechanical Systems (MEMS)

Background:

• Fiber-optic sensors offer advantages in harsh environments.
• Microelectromechanical Systems (MEMS) enable miniaturization and enhanced performance.
• Intensity-modulated sensors provide a simple demodulation mechanism.

Purpose of the Study:

• To propose and experimentally demonstrate a reflective intensity-modulated fiber-optic sensor for pressure measurements.
• To leverage MEMS technology and fiber optic design for high-sensitivity pressure sensing.
• To evaluate the sensor's performance characteristics, including sensitivity, temperature stability, and dynamic response.

Main Methods:

• Fabrication of a sensor integrating multimode optical fibers with spherical ends, a dual-hole quartz tube, a silicon diaphragm, and a high borosilicate glass substrate.
• Utilizing a reflective intensity-modulation mechanism for pressure detection.
• Characterization of sensor sensitivity, temperature coefficient, and dynamic response.

Main Results:

• Achieved a pressure sensitivity of approximately 0.139 mV/kPa.
• Demonstrated a low temperature coefficient of about 0.87 mV/°C across a wide temperature range (20 °C to 150 °C).
• Verified real-time response to high-frequency pressure (1 kHz) in a dynamic environment.

Conclusions:

• The proposed MEMS-based fiber-optic sensor is a viable solution for accurate and real-time pressure measurements.
• The sensor's design offers high sensitivity and good temperature stability.
• The simple intensity-modulation mechanism facilitates straightforward demodulation and high-frequency dynamic response capabilities.