High sensitivity gas pressure sensor based on different inner diameter quartz capillary cascading and Vernier effect

Area of Science:

• Photonics and Sensing Technologies
• Optical Fiber Sensors
• Gas Pressure Measurement

Background:

• Accurate gas pressure sensing is crucial in various industrial and environmental applications.
• Existing sensors often face limitations in sensitivity, size, or manufacturing complexity.
• Optical fiber sensors offer advantages like remote sensing and immunity to electromagnetic interference.

Purpose of the Study:

• To propose and experimentally verify a highly sensitive optical fiber gas pressure sensor.
• To leverage the optical Vernier effect for enhanced gas pressure detection.
• To demonstrate a cost-effective and easily manufactured sensor design.

Main Methods:

• Fabrication of a sensor comprising two Fabry-Pérot (F-P) cavities using single-mode fiber and quartz capillaries.
• Utilizing a small inner diameter capillary as a gas channel.
• Achieving the optical Vernier effect by precisely adjusting capillary lengths for closely matched free spectral ranges.

Main Results:

• The sensor demonstrated high gas pressure sensitivity of -81.73 nm/MPa within a 0-0.8 MPa range.
• Excellent linearity of 99.7% was achieved for gas pressure detection.
• Low temperature cross-sensitivity of 1.82 kPa/°C was observed.

Conclusions:

• The proposed optical fiber gas pressure sensor offers a highly sensitive and linear measurement solution.
• Its simple manufacturing process, compact structure, and small volume make it suitable for large-scale gas sensing applications.
• The sensor represents a promising advancement in optical fiber sensing technology for gas pressure monitoring.