Fiber optical sensors are a new type of sensor-technology which has been in development for over 30 years, and the interest for the fiber technology has increased exponentially. The reason for this is because of its many advantages such as; electromagnetic immunity, size and weight reductions, and cost reduction. Even though the fiber optic sensor has many advantages, it still faces other challenges. A fiber optical sensor can for example be used to measure acoustic waves, which is a typical application for the sensor. However, one of the challenges is that the fiber optic sensor can be disturbed by an unknown thermal fluctuation. In this project we will develop technology for a control algorithm which will compensate for this unknown thermal fluctuation. During this project the fiber optical sensor; Fiber Bragg Grating, will be used to measure acoustic waves on a steel plate. For initial test a tuneable laser diode has been used, which then was be replaced with a superluminescent diode and a reference Fiber Bragg Grating. The results were that it was possible to measure acoustic waves with a tuneable laser diode. However when replacing the laser diode with a superluminescent diode and a reference Fiber Bragg Grating, the optical power was too low for the photodetector to
measure any change in optical power.