RESUMO
The application of quantum dot (QD) semiconductor optical amplifiers (SOAs) in above 100-Gbit Ethernet networks demands an ultrafast gain recovery on time scales similar to that of the input pulse approximately 100 GHz repetition frequency. Microscopic scattering processes have to act at shortest possible time scales and mechanisms speeding up the Coulomb scattering have to be explored, controlled, and exploited. We present a microscopic description of the gain recovery by coupled polarization- and population dynamics in a thermal nonequilibrium situation going beyond rate-equation models and discuss the limitations of Coulomb scattering between 0D and 2D-confined quantum states. An experiment is designed which demonstrates the control of gain recovery for THz pulse trains in InGaAs QD-based SOAs under powerful electrical injection.
RESUMO
pSP64 derivatives were constructed to obtain cloning vectors suitable for in vitro transcription and subsequent in vitro synthesis of recombinant proteins equipped with N-terminal signal sequences. The amino acid sequence of the signal peptide was adapted and slightly modified from the one occurring in the neural cell adhesion molecule, NCAM. Its ability to direct recombinant proteins into secretory pathways was tested by in vitro translation in microsomal membrane-containing reticulocyte lysates and by injection of the pUMA-derived cRNAs into Xenopus laevis oocytes.
