The inter-instrument, inter-laboratory, and long-term comparability of fluorescence data requires the correction of the measured emission and excitation spectra for the wavelength- and polarization-dependent spectral irradiance of the excitation channel at the sample position and the spectral responsivity of the emission channel employing procedures that guarantee traceability to the respective primary standards. In this respect the traceability chain of fluorometry is discussed from a radiometrist's point of view. This involves, in a first step, the realization of the spectral radiance scale, based on the blackbody radiator and electron storage ring, and the spectral responsivity scale, based on the cryogenic radiometer and their control via key comparisons of the national metrology institutes. In a second step, the characterization including state-of-the art uncertainties of the respective source and detector transfer standards such as tungsten strip lamps, integrating sphere radiators, and trap detectors used to disseminate these radiometric quantities to users of spectroscopic techniques is presented.

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Two-particle (exciton) states in equilibrium electron-hole plasmas of highly excited semiconductors are determined. In the framework of the Green's function technique, an effective (two-particle) wave equation allows to account for the influence of the surrounding plasma in terms of (dynamic) single-particle self-energies, Pauli blocking factors, and a dynamic effective potential correction. This equation is solved by expansion of the wave function in terms of Coulomb eigcnfimctions. No rational or pole approximation for the dielectric function is used. Exciton binding mcrgics and their imaginary parts (damping of the states) as well as continuum edges are given for Ge and GaAs model systems.Es werden Zwei-Teilchen-(Exzitonen-)Zustande in Elektron-Loch-Gleichgewichtsplasmen in hochangeregten Halbleitern bestimmt. Im Rahmen der Green-Funktionstechnik kann in einer effektiven (Zwei-Teilchen-) Wellengleichung der EinfluB des umgebenden Plasmas durch (tlynarnische) Ein-Teilchen-Selbstenergien, Phasenraumverbrauchsfaktoren und eine dynamische effektive Potcntialkorrektur beriicksichtigt werden. Diese Gleichung wird mittels Entwicklung der Wellenfunktion nach Coulomb-Eigenfunktionen gelost. Eine rationale oder Pol-Naherung fur die diclektrische Furiktion wird nicht verwendet . Exzitonen-Bindungsenergien und ihre Imaginarteile (Dampfung der Ziistande) sowie Kontinuumskanten werden fur ein Ge-und ein GaAs-Iblodellsystein angegeben.