Er doped concentric cores optical fiber for simultaneous amplification and compe

The Er-doped concentric-cores dispersion compensating fiber (EDDCF) has been demonstrated. The rare earth has been doped as a ring around the inner core. We have obtained 14-dB gain at 1550 nm (using 100-mW pump power and 980-nm wavelength) with dispersion of about -165 ps/(km.nm). It is useful for