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Four-level rate equation model is used to describe the carrier dynamics in quantum dot (QD) semiconductor optical amplifiers (SOAs) which takes into account the effect of QD continuum state. A phenomenological description is used to model the intradot carrier scattering between discrete quantum dot states and the continuum state. Analytical results are presented for the small-signal response of wavelength conversion based on the four-wave mixing and cross gain modulation in these advanced amplifiers.

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Dr. Warid Was born in Baghdad, Iraq, in 1977. He received the B.Sc, M.Sc, and Ph.D. degrees from Al-Mustansiriyah University, Baghdad,Iraq, in 2001 2004, and 2012, respectively. His research interests include modeling of semiconductor quantum-dot lasers and amplifiers, and nonlinear laser dynamics.

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