Quantum optics in semiconductors

Piotr Konrad Kondratko, Akira Matsudaira, Shu‐Wei Chang +1 more

Slow and fast light in quantum-well (QW) and quantum-dot (QD) semiconductor optical amplifiers (SOAs) using nonlinear quantum optical effects are presented.We demonstrate electrical and optical controls of fast light using the coherent population oscillation (CPO) and four wave mixing (FWM) in the gain regime of QW SOAs.We then consider the dependence on the wavelength and modal gain of the pump in QW SOAs.To enhance the tunable photonic delay of a single QW SOA, we explore a serial cascade of multiple amplifiers.A model for the number of QW SOAs in series with variable optical attenuation is developed and matched to the experimental data.We demonstrate the scaling law and the bandwidth control by using the serial cascade of multiple QW SOAs.Experimentally, we achieve a phase change of 160 • and a scaling factor of four at 1 GHz using the cascade of four QW SOAs.Finally, we investigate CPO and FWM slow and fast light of QD SOAs.The experiment shows that the bandwidth of the time delay as a function of the modulation frequency changes in the absorption and gain regimes due to the carrier-lifetime variation.The tunable phase shift in QD SOA is compared between the ground-and first excited-state transitions with different modal gains.

W. Hoyer, M. Kira, Stefan W. Koch

M. Kira, S. W. Koch

The optically generated excitations in semiconductors constitute a genuine many-body system. To describe its quantum-optical features, we have to expand significantly the theoretical models used so far. However, the important insights of Chapters 16–23 are already presented in a form in which most of them can directly be used and generalized to analyze central properties of the optical excitations in solids. As for atoms, the optical transitions in semiconductors are induced via dipole interaction between photons and electrons. We can thus efficiently construct a systematic quantum-optical theory for semiconductors by following the cluster-expansion approach. One of the main differences from atoms is that the electronic excitations in semiconductors form a strongly interacting many-body system. Thus, we must systematically treat the arising Coulomb-induced hierarchy problem together with the quantum-optical one. Moreover, the coupling of electrons to lattice vibrations, i.e., the phonons, produces yet another hierarchy problem. In addition, in solid-state spectroscopy one often uses multimode light fields such that one cannot rely on the single-mode simplifications to study semiconductor quantum optics. As shown in Chapter 15, the Coulomb-, phonon-, and photon-induced hierarchy problems have formally an identical structure. Thus, we start the analysis by investigating how semiconductor quantum optics emerges from the dynamics of correlated clusters. We first focus on the basic properties of the optical transitions in the classical regime. This means investigating the fundamental optical phenomena resulting from the singlets. The full singlet–doublet approach is presented in Chapters 28–30.

H. Haug, Antti‐Pekka Jauho

Ataç İmamoğlu

Kambiz Abedi, H. Taleb

In this paper, optimal design of a pumping scheme for achieving the best gain and phase response in quntum--dot semiconductor optical ampliers is investigated.For the rst time, the dynamic response of the quntum-dot semiconductor optical amplier is evaluated under three dierent pumping schemes, known as optical pumping, electrical pumping, and electro-optical pumping.Simulation results show that the shortest gain recovery time in quntum-dot semiconductor optical ampliers can be achieved under the electrical pumping scheme.However, under the optical pumping and electro-optical pumping schemes, the quntum-dot semiconductor optical amplier represents a shorter phase recovery compared to the electrical pumping scheme.We found that a sub-nanosecond phase recovery in the quntum-dot semiconductor optical amplier can be achieved under the OP and electro--optical pumping schemes, which can never be achieved under the electrical pumping, because of the slow carrier dynamics of the carrier reservoir.Also, it was found that the gain recovery process in an optically pumped quntum-dot semiconductor optical amplier can be signicantly accelerated at cryogenic temperatures.This result demonstrates the superiorities of the optical pumping scheme over the electrical pumping and electro-optical pumping schemes at low temperatures, where both the gain and phase recovery times of an optically pumped quantum-dot semiconductor optical amplier are drastically decreased.