The linear optical properties in quantum dots under a single coupling field

Using the density matrix method, the linear optical properties of truncated pyramid quantum dots have been investigated when an additional coupling field is introduced. The absorption coefficients and refractive index changes are strongly affected by the amplitude of the coupling field and the phase difference between the probe and coupling fields. The numerical results indicate that negative absorption and transparency can be obtained when both of the probe and coupling fields are in resonance with the quantum dots.