Low-cost multiple FBG interrogation technique for static applications.

In this Letter, a low-cost interrogation technique for multiple fiber Bragg gratings (FBGs) is demonstrated. The design utilizes the major advantage of the distributed feedback lasers, which is tuning their emitted wavelength by current modulation and temperature variation. The sensitivity of this method and the influence of optical losses on the measurement have been carefully studied, and an accuracy of 5 pm is achieved.