Interferometric Measurements Of Linewidth And Phase Noise Of An Er-doped Fiber Ring Laser

A measured linewidth of < I0kHz and a phase noise level of ~ 20 /spl mu/rad//spl radic/Hz (measured with a 3m unbalanced interferometer) are reported for an Er-doped fiber ring laser with an intra-ring fiber birefringent spectral filter. The effects of acoustical and vibrational shielding on these measurements are also reported.