Gain- and noise-figure improvement of a reflective L-band EDFA by using a short length of preamplification EDF

A reflective long-wavelength-band erbium-doped fiber amplifier (L-band EDFA) with enhanced gain and improved noise figure is demonstrated. By utilizing a short length of erbium-doped fiber (EDF) before an optical circulator (OC), the population inversion at the input of this EDFA is intensified, which gives rise to the noise-figure improvement. Compared with the conventional one, our novel reflective EDFA provides noise improvement of 2.2–23.9 dB and gain enhancement of 2.3–12.6 dB throughout an approximate wavelength region from 1568 to 1594 nm. We also observe the gain evolution under different amounts of prestage pump power and average gain and noise figures of 32.2 and 8.1 dB, respectively, are achieved with a prestage pump power of 69.5 mW. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 60–62, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20723