We report level bleaching in the ground state of a single In_(0.5)Ga_(0.5)As quantum dot. This behavior arises from the nonlinear absorption of a single quantum state. The level bleaching is observed in terms of a saturation of the photocurrent with increasing excitation power under the condition of resonant excitation in the quantum dot ground state. Furthermore, the photocurrent saturation is put down to a fundamental rate equation model. The steady-state solutions are in good agreement with the experimentally observed power dependence of the photocurrent.
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