Dynamic characterization of output power fluctuations in FBG stabilized 14xx-nm GaInAsP/InP laser modules

Output power stability of 14xx-nm GaInAsP/InP laser module with fiber Bragg gratings (FBGs) for Raman amplifiers was dynamically evaluated. Power fluctuations accompanied by wavelength jumps to the gain peak were observed by single-FBG configuration. On the other hand, double-FBGs configuration having same coherent reflectivity as the single-FBG showed stable output power.

1. Introduction

Fiber Raman amplifiers are attractive for large capacity optical communication systems with advanced multi level formats because of their low noise characteristic as well as suppression of the nonlinearity of the transmission media. High power 14xx-nm GaInAsP/InP laser modules are used as pump sources for the amplifiers. The wavelength of the laser is controlled by fiber Bragg gratings (FBGs). However, the output power is essentially unstable due to the optical feedback by the FBG [1], [2]. We already reported the stabilization of the output power by using single- and double-FBG laser diode modules [3], where we found the latter is more stable with suppression of Fabry-Perot emission at the gain peak wavelength. In this study, we compare dynamic behavior of the power fluctuation between single-and double-FBG configurations.