Efficient and low‐noise gain‐flattened double‐pass L‐band erbium‐doped fiber amplifier

Abstract

A new double-pass long-wavelength-band erbiumdoped fiber amplifier with enhanced noise figure characteristics is demonstrated by adding a short length of forward pumped erbiumdoped fiber (EDF) in front of the double-pass amplifier. By adding 7 m of EDF, the amplifier achieves a flat-gain output at about 34.2 dB with a gain variation of less than 1.3 dB at the wavelength region 1568 -1598 nm. The corresponding noise figures vary from 5.0 to 5.7 dB, which is improved by 1.7 to 7.5 dB over the flat-gain region, as compared to that of the conventional double-pass amplifier. This new amplifier with high gain and low noise figure can be useful as an inline amplifier in a wavelength division multiplexing transmission system.

Gain and noise figure enhancements of both C and L bands double pass Erbium Doped Fiber Amplifier

“…These are single pass EDFA [24][25][26], double pass EDFA [27][28][29][30][31], many pass EDFA configurations [32][33][34], artificial intelligence applications [35][36][37][38], and temperature characterization [39][40][41][42][43]. In addition, some studies are related to both gain improvement and noise figure in double pass EDFA [44][45][46][47][48][49][50][51][52] proposed an efficient and low noise double-pass L-Band EDFA in their studies [59][60][61].…”

The noise figure and gain improvement of double‐pass C‐band EDFA

“…Therefore, high gain and low NF are very important parameters to increase transmission distance and optical repeaters number of in the transmission systems. There are many studies in literature about this issue . Generally, double pass systems are used to increase the EDFA gain .…”