Simulation and Experimental Validation of Gain-Control Parallel Hybrid Fiber Amplifier

Abstract

We demonstrate a simulation of a parallel hybrid fiber amplifier in the C+L-band with a gain controlling technique. A variable optical coupler is used to control the input signal power for both EDFA and RFA branches. The gain spectra of the C+L-band are flattened by optimizing the coupling ratio of the input signal power. In order to enhance the pump conversion efficiency, the EDFA branch was pumped by the residual Raman pump power. A gain bandwidth of 60 nm from 1530 nm to 1590 nm is obtained with large input signal power less than -5 dBm. The gain variation is about 1.06 dB at a small input signal power of -30 dBm, and it is reduced to 0.77 dB at the large input signal power of -5 dBm. The experimental results show close agreement with the simulation results.

Widely Flatness Gain Bandwidth with Double Pass Parallel Hybrid Fiber Amplifier

“…3 c. The results clearly showed the satisfactory performance of the proposed amplifier, which can operate up to -15 dBm without a saturation effect. Finally, the results of our design exhibited a wider gain bandwidth and larger gain level compared with the findings in [9,10,11,12,13,14,15,16,17,18]. Table 1 summarizes the results of the performance evaluation of our work and previous studies.…”

Widely flatness gain bandwidth with double pass parallel hybrid fiber amplifier

“…However, flatness gain bandwidth was reduced to 45 nm (1555-1600) and no study was conducted at low input signal power. Parallel HFA (PHFA) was proposed by many researchers to avoid gain saturation and limited gain dynamic range caused by the cascading process in SHFA [10,11,12,13,14]. The cascading effect was absent, but the signal was divided into two different individual amplifiers for re-accumulation in the PHFA.…”

“…Therefore, a large input signal power can induce degradation in the EDFA branch. The input signal power was divided into two PHFA branches instead of dividing the input signal wavelength to prevent this limitation [13,14]. Gain control technique is used in PHFA to control the amount of input signal power to each amplifier.…”

Optical Fiber Amplifiers: Optimization and PerformanceEvaluation

“…The OFA is simply a fiber laser with the absence of the positive feedback, and can be classified into two categories, namely, linear OFA (rare earth doped fiber amplifier) and nonlinear OFA (Raman and Brillouin fiber amplifier). The most popular linear OFA is the EDFA because it covered the low loss conventional communication band [1]. While the RFA is the common nonlinear FA due to the following points: (i) the gain can be achieved at any communication band within the proper pumPing wavelength choice; (ii) very fast amplification processes; (iii) wide amplification bandwidth [2].…”