Controlled Fabrication System of Fabry-Perot Optical Fiber Sensors

The use of optical fiber sensors is increasing widely in industry, civil, medicine, defense and research. Among different categories of these sensors is the Extrinsic Fabry-Perot interferometer (EFPI) sensor which is inherently simple and requires only modest amount of interface electronics. These advantages make it suitable for many practical applications. Investigating a cost-effective, reliable and repeatable method for optical fiber sensor fabrication is challenging work. In this thesis, a system for controlled fabrication of Fabry-Perot optical fiber sensors is developed and presented as the first attempt for the long-term goal of automated EFPI sensor fabrication. The sensor fabrication control system presented here implements a real-time control of a carbon dioxide (CO₂) laser as sensor bonding power, an optical fiber white light interferometric subsystem for real-time monitoring and measurement of the air gap separation in the Fabry-Perot sensor probe, and real-time control of a piezoelectric (PZT) motion subsystem for sensor alignment. The design of optoelectronic hardware and computer software is included. A large number of sensors are fabricated using this system and are tested under high temperature and high pressure. This system as a prototype system shows the potential in automated sensor fabrication.