Effect of ring parameters on wavelength characteristics of erbium fiber lasers

We present detailed experimental results on the dependence of lasing wavelength of erbium doped fiber ring laser (EDFRL) on fiber length, feedback coupling ratio and intra-cavity loss. No wavelength selective elements are included in the laser cavity. The feedback ratio is varied from 1% to 99% by changing the coupler in the cavity. Intra-cavity loss is varied up to 30 dB using a variable optical attenuator (VOA). Output characteristics are studied for 3 different fiber lengths. Longer length of fiber, higher feedback ratio and low cavity loss provides larger wavelength tuning range.