We show that a wide-band noise source can be used to accurately measure the large-signal gain spectrum of an EDFA. Even in a range where spectral hole burning has a significant impact. Data is presented for a comparison of our technique, with the more conventional method.
Gain-difference spectra are used to show that 980-nm band pump wavelength changes can significantly effect spectral-hole burning (SHB) in erbium-doped fiber amplifiers (EDFAs). Gain measurements made using a number of different signal and pump wavelengths help to characterize the underlying inhomogeneous spectral properties of EDFAs and a framework for modeling these effects is presented. Despite the difficulty of obtaining the needed subpopulation specific cross section spectra, this model can be used to explain seemingly anomalous changes in the gain spectra of EDFA as a result of changes in signal or pump wavelength.