Shorter Wavelength Gain Shift In EDFA Using A Macro-Bending Approach

Gain and noise figure improvements are demonstrated in a shorter wavelength region of double-pass EDFA using a macro-bending approach. The EDF is wound in a small radius to suppress the amplified spontaneous emission at the longer wavelength in order to achieve a high amplification in the shorter wavelength. Gain enhancements of about 12 ~ 14 dB are obtained with macro-bending at wavelength region between 1480 nm and 1530 nm. The micro-bending also reduces the noise figure of the EDFA at wavelengths shorter than 1525 nm with maximum improvement of 25 dB.