All silica S-band double-pass erbium-doped fiber amplifier

Switchable dual-wavelength erbium-doped fiber ring laser using bending dependent loss to switch the operating wavelength

“…A larger feedback ratio corresponds to a longer lasing wavelength due to the relatively longer trip. As demonstrated in previous works [12,13], spooling the EDF with various diameters results in quite different gain profiles. Small diameter of the EDF loop corresponds to blue shift (shift toward short wavelengths) of the gain profile.…”

Doped fiber lasers: From telecom to industrial applications

“…For example, through the suppression of the Amplified Spontaneous Emission (ASE) in the C band by exploiting the fundamental mode cutoff of a depressed-cladding doped fiber [7] or by inserting multiple filters within the amplifier module [8], thus increasing its complexity and cost. Another approach relies on the ASE suppression by simply exploiting the bending losses of a depressed-cladding fiber properly bent and doped [9][10][11]. Using this technique, both S band amplifiers and tunable lasers have been proposed and experimentally verified.…”

Efficient S-Band Amplification Using Depressed-Cladding Erbium-Doped Silica Fibers

“…We have used those fibers to develop a series of S-Band EDFAs. The first of those was a single stage double-pass configuration, using a single amplification stage and a single pump laser [3]. This double-pass (DP) configuration had been previously proposed by us [4].…”

“…It is demonstrated that the double pass topology shows much improved gain performance compared to the single pass configuration although the noise figure is degraded by counterpropagating ASE [3]. Next, the double pass topology was modified to to achieve signal amplification simultaneously over S, C and L bands.…”