Controlling and Tuning the Emission of Semiconductor Optical Amplifier for Sensor Application by Means of Fiber Bragg Gratings

摘要

Highly sensitive and selective sensing has become more and more important in modern process control and security related fields. For this purpose, we have designed a novel tunable fiber based external cavity laser system for sensor applications. The laser consists of a semiconductor optical amplifier (SOA) as a gain medium and of Fiber Bragg Gratings (FBG) as wavelength selective components. Since the SOA is an inhomogeneous broadening gain medium, stable multi-wavelength oscillation at the Bragg wavelengths of the FBGs used can be obtained. In addition, the oscillation wavelengths of the laser can be tuned by applying temperature and strain to the FBGs. Simultaneous measurements of the FBGs temperature stabilization and tuning of the sensor outputs are achieved. In the sensor scheme, the two-wavelength components provide narrowband light sources for sensor applications and the wavelength tuning enables a wide range for target absorption detection.