Fiber Fabry-perot Micro-interferometer Demodulation Method And Its Application

The emerging fiber-optic sensors represent a development trend of new generation sensor, with many advantages, such as simple structure, small size, light weight, free from electromagnetic interference, good stability, high accuracy, easy networking and so on, has been widely applied to industrial and military fields including energy, transportation, architecture, medicine, aerospace etc. Fiber optic sensor industry has been recognized as the most promising one of high-tech industry at home and abroad, and attracted worldwide attention due to its high content of science and technology, good economic returns, penetration ability, and broad market prospects etc. With China's rapid economic development and advancement of the internet of things development strategy, China's optical fiber sensor research and industrialization are also facing great opportunities and challenges. The fiber Fabry-Perot sensor is an important branch of optical fiber sensors, which mainly uses intensity demodulation and phase demodulation. The traditional single-wavelength intensity demodulation method is vulnerable to be affected by fluctuations in light intensity, optical path disturbance, optical fiber transmission loss changes, and the electrical parameter drift etc., making it less practical engineering application, generally only in the laboratory do some research and the like attempt. Therefore, to improve and perfect the fiber Fabry-Perot sensor production and demodulation method has a profound theoretical and practical significance. Based on this starting point, this paper completes a series of work, summarized as follows:(1) Referencing a large number of documents and patents, this paper analyzed domestic and foreign research status and development trends on optical fiber sensor to provide some reference for fiber optic sensor research and industrialization, at the same time summed up the current fiber optic sensor various structures, manufacturing method, demodulation method, and analyzed and compared their advantages and disadvantages.(2) Proposed a new optical fiber Fabry-Perot sensor dual-wavelength demodulation method based on carrier technology, and in-depth studied the principles of the method, and then built a hardware system, designed the demodulation software, completed the validation experiments. This method, due to two wavelengths signal through the same path and circuit, virtually eliminates light intensity fluctuations, optical path disturbance and the electric parameter drift effects by divided.(3) Researched the method using CZT transform method to demodulate fiber Fabry-Perot sensor theoretically and experimentally. Studied method of using 157nm laser micro-processing technology to produce optical fiber Fabry-Perot cavity, and Developed a pressure measurement system that is expected to work under extreme harsh conditions such as aerospace, energy industry and so on, which provide a practical way to resolve the long-standing problems in the world of hard to accurate measurement under high temperature environment.