Narrow linewidth continuous-wave and gain-switched fiber laser with intracavity unpumped Er-doped fiber loop

Abstract

Investigation has been performed for the characteristics of the fiber ring laser incorporating an intracavity unpumped Er-doped fiber Sagnac loop for narrow linewidth continuous wave (CW) and gain-switched pulsed operation. The gain-switched pulse has duty cycle of 4.4% with more than 113 mW in peak power at the reflective optical filter output and the laser was stable both in output power and the peak wavelength.