A Four-Wavelength All-Fiber Laser for Wavelength DivisionMultiplexing System

A novel four-wavelength all-fiber laser based on fiber Bragg gratings is presented. The four wavelengths are 1555.8, 1556.6, 1557.4 and 1558.2 nm, respectively. Each output laser is < 0.3 nm in line-width and > 1 mW in power. The suppression ratio between adjacent wavelengths is > 30 dB. The laser was applied in a wavelength division multiplexing (WDM) system and the 100 km transmission of 1.2 Gb/s nonreturn-to-zero code, 1.2 Gb/s return-to-zero code, 2.5 GHz analogue signal and 5 GHz analogue signal was realized with it.