Three-stage six-pass EDFA preamplifier design and EDFA parameters’ optimization

In this study, three-stage six-pass erbium doped fiber amplifier (EDFA) is performed. The mathematical model to characterize this proposed EDFA are also developed. During the design process, EDFA’s input signal wavelengths, EDF lengths and pump powers are optimized. Four different types of commercial fibers such as I6, I25, M5 and M12 are used and compared with each other. A one-stage double-pass block is cascaded three times which forms the three-stage six-pass preamplifier design. In every double-pass block; an EDF, a coupler, a circulator and a mirror are used. Input signal is multiplexed with the pump in the coupler, then passing through the circulator and amplified over the first EDF. After that, the amplified signal reflected from the mirror and makes its second pass over the same EDF. This scheme repeated three times to form the presented study in this paper. In scope of this design, 1528–1566 nm input signal wavelength spectrum is used for all fiber types with 2 nm span. In -50 dBm input signal power at 1532 nm, 1480 nm and 200 mW pump powers for I6, I25, M5 and M12 fibers 57.36, 59.23, 58.95 and 58.89 dB gain and 3.86, 3.43, 3,30 and 3.11 dB noise figure values are obtained respectively.