Abstract :
Erbium-doped fiber amplifiers (EDFAs) seem to be promising candidates for constructing rapidly tunable, widely tunable, single-frequency, single-polarization 1.55 μm sources. However, simultaneously attaining all these characteristics has proved to be difficult. Much work has avoided using polarization-maintaining (PM) EDF to enhance affordability, availability, and flexibility. The observation that the Faraday rotator mirrors (FRM) can compensate for the effects of fiber birefringence suggests that the state of polarization (SOP) is orthogonal to the input SOP everywhere in the fiber (referred to as "orthoconjugate"). This led many to conclude that spatial hole burning could be eliminated by using a FRM in an EDFA. Unfortunately, the orthogonality of so-called "orthoconjugate" waves are based on a change of coordinate system. To analyze spatial hole burning a fixed coordinate system is required to properly add any coincident electromagnetic fields. To show the effects attributed to interference of counterpropagating waves within a gain fiber are not eliminated by using an FRM, two single-polarization ring laser configurations are compared
Keywords :
Faraday effect; erbium; fibre lasers; laser mirrors; optical fibre polarisation; optical hole burning; ring lasers; 1.55 mum; Er fiber lasers; Er-doped fiber amplifiers; Faraday rotator mirrors; counterpropagating waves; fiber birefringence; fixed coordinate system; gain fiber; orthoconjugate; polarization-maintaining Er-doped fiber; rapidly tunable sources; single-frequency sources; single-polarization ring laser configurations; single-polarization sources; spatial hole burning; state of polarization; widely tunable sources; Birefringence; Electromagnetic analysis; Electromagnetic fields; Erbium; Erbium-doped fiber amplifier; Erbium-doped fiber lasers; Interference elimination; Mirrors; Optical fiber polarization; Tunable circuits and devices;
