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Uncorrelated Optical Transitions

  • Wilfried Schäfer
  • Martin Wegener
Part of the Advanced Texts in Physics book series (ADTP)

Abstract

In a semiconductor, there is a wealth of possible transitions between electronic states mediated by a photon. Figure 4.1 summarizes a number of them. As typical photon wave vectors are negligible with respect to the extent of the Brillouin zone, the photon looks practically like a vertical line in the energy dispersion diagram.1 Direct interband transitions (Fig. 4.1a,b), direct inter-valence-band transitions (Fig. 4.Id) and similarly direct inter-conduction-band transitions, and photoemission (Fig. 4.If) directly connect an occupied initial state (filled circles) to an empty final state (open circles). Intra-conduction-band (Fig. 4.1c) and similarly intra-valence-band transitions, and indirect interband transitions (Fig. 4. 1e) on the other hand, require a phonon to be emitted or absorbed in addition. Clearly, at low temperatures, only emission remains (only this channel has been drawn in Fig. 4.1). Transitions requiring both a photon and a phonon are generally much weaker than the others and are usually only of relevance when other transitions are absent in a particular energy regime.

Keywords

Rabi Frequency Nonlinear Optical Property Bloch Equation Linear Optic Bloch Vector 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2002

Authors and Affiliations

  • Wilfried Schäfer
    • 1
  • Martin Wegener
    • 2
  1. 1.Forschungszentrum Jülich GmbHJohn von Neumann - Institut für ComputingJülichGermany
  2. 2.Institut für Angewandte PhysikUniversität Karlsruhe (TH)KarlsruheGermany

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