Short cavity single-frequency all-fiber Er/Yb co-doped laser

Abstract

A 5-cm-long Er/Yb co-doped all-fiber laser is studied. Two fiber Bragg gratings (FBGs) are written in the Er/Yb co-doped sensitive fiber using UV beams. A 980?nm pumping laser diode (LD) is used, and output wavelength is selected by two FBGs. The single-frequency laser is achieved at 1544.68?nm. The 3?dB spectrum width is 0.08?nm, while the side mode suppression ratio is 55?dB. The maximum output power exceeds 4?mW for pump power of 140?mW and the stability is less than ±0.01?dB. Single-frequency operation is verified using a scanning Fabry-Perot (F-P) interferometer. Relative intensity noise is less than −100?dB. A 10?Gbit/s code rate is used in the fiber laser transmission experiment. A good optical eye diagram is received after 21?km single-mode fiber transmission. A simple distributed Bragg reflection(DBR) fiber laser array is designed. The wavelength difference of output laser array is 0.8?nm, conforming to the ITU―T channel spacing standard of wavelength-division multiplexing systems.