Novel 1500 nm-band EDFA with discrete Raman amplifier

Doped fiber lasers: From telecom to industrial applications

“…It is particularly attractive, being characterized by low loss in silica optical fibers. New amplifier modules for S band have been investigated as well, and the main candidates for this purpose could be fluoride-based thulium-doped fiber amplifiers [4,5] and Raman amplifiers [6]. However, while the formers pose issues regarding the reliability of fluoride fibers, the latters require high pump powers, which enhance undesired nonlinear effects.…”

Tunable passively Q-switched thulium-doped fiber laser operating at 1.9 μm using arrayed waveguide grating (AWG)

“…An optical isolator is also used to force the unidirectional propagation in a ring configuration. There have been numerous reports of amplification in the S-(1480-1520 nm) [1][2][3][4], C-(1540-1560 nm) [5][6][7] and L-(1560-1600 nm) [8][9][10] bands which can be configured easily into a fiber laser. Due to the rapid increase of the demand of data traffic, there has been interest in the 2 mm band region as to complement the existing bands, whereby thulium is the active medium.…”

S-band gain-flattened EDFA with two-stage double-pass configuration

“…In order to obtain S-band gain, it is crucial to substantially suppress the C-band ASE and maintain a high population inversion (inversion rate > 70 %) in S-band [6] . Employing an EDF with depressed inner cladding design is a distributed filtering approach.…”