Erbium-doped fibre ring laser based on microfibre coupler

Abstract

A compact erbium-doped fibre (EDF) laser is demonstrated which uses a microfibre coupler and a highly concentrated EDF loop. The coupler functions to inject the pump light and tap out the output. The EDF laser operates at 1526.3 nm, with a signal-to-noise ratio of about 26 dB. The maximum output power 20 μW is obtained at the pump power 18.6 mW. We have obtained the slope efficiencies of the laser 0.12, 0.06, 0.04 and 0.02% at the EDF lengths fixed at 90, 78, 66 and 51 cm, respectively. The lowest lasing-pump power threshold is achieved at 3.8 mW.