Study On Erbium Doped Fiber Ring Laser

The optic communications technology is one of the greatest achievements in 20th century , It is regard as the base of Infobahn . And the better lasers are wanted to suit the wide use of WDM and OTDM.In this thesis,Based on the character of the EDF gain at 1550nm,a laser diode (980nm) acted as the pumping source, a Bragg grating used as filter,a ring-cavity all-fiber laser worked at 1550.295 nm was demonstrated with an output power of 45 mW and a bandwidth of 0.05 nm at 3dB. It's capabilities are better than laser diode.Meanwhile, the theory of EDF laser was discussed. The experiment showed that the output power of the laser was related with the length of EDF,the coupled-ration of output coupler.Then the fit length of EDF and fit couple-ration of output coupler was gained.The driving circuit of the laser diode was designed and have been used to stabilized the output power of the laser. Finally a tunable fiber Bragg grating ring laser with narrow line width of 0.05nm at 3dB and tunable output was demonstrated.Its tuning rang was up to 0.74nm.