Fiber-tip air cavity sealed by cutting-free inwardly concave silica diaphragm cascaded to fiber Bragg​ grating for gas pressure sensing

Fiber-tip air cavity sealed by cutting-free inwardly concave silica diaphragm cascaded to fiber Bragg grating for gas pressure sensing is proposed. According to the measured experimental data, the proposed fiber-tip air cavity respectively has its pressure sensitivity of 9.79 nm/MPa, temperature sensitivity of 2.61 pm/°C which induces a pressure detection error of 3.55 kPa/°C. The experiment results show that the proposed fiber-tip air cavity possesses the advantages of appropriate pressure measuring sensitivity, low temperature sensitivity and temperature induced pressure detection errors, and it is suitable for practical gas pressure sensing.