Measurement of 3-dB linewidth of FBG Fabry-Perot interferometer using tunable fiber laser

Abstract

We present a simple method to measure the 3 dB linewidth of the sharp peak in the spectrum of the fiber Bragg gratingbased Fabry–Perot (FBG-FP) interferometer. A narrow linewidth tunable laser is used for sweeping the FBG-FP to achieve the reflection spectrum. A triangle wave is used to drive the narrow linewidth tunable laser. The linewidth of the sharp peak is measured with a resolution of 0.001 pm.