We characterized the temperature response of a ytterbium (Yb) system by measuring its temperature-dependent emission and absorption spectra and deriving parameters characterizing transitions among Stark levels by Lorentzian curve fitting. We found that even weak transitions in the Stark levels are distinct enough for this procedure when using a linear combination of measured spectra at and . A fiber amplifier model was established to determine temperature-dependent performance of Yb-doped fiber amplifiers. We concluded that the temperature dependence of the Yb-doped fiber amplifier is mainly determined by the saturation level , when ; the higher the saturation levels, the less temperature dependence. When operating a Yb-doped fiber amplifier at low saturation, the temperature dependence is mainly determined by changes in absorption and emission coefficients at the signal wavelength and is the worst when operating around the short wavelength of .
© 2008 Optical Society of America
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