We report the fabrication of a single-mode solid-state single photon source, based on an isolated InAs quantum dot (QD) on resonance with the fundamental mode of a pillar microcavity. Photon correlation experiments under pulsed excitation reveal a clear antibunching behavior. We show that a preparation of the single photons in a given quantum state (same spatial mode, same polarization) can be obtained by placing a QD in resonance with the nondegenerate fundamental mode of an elliptical micropillar.

No abstract

ECMWF's preparations for cloud and rain assimilation encompass development of linearized physics, improved satellite data utilization, a new humidity analysis, and another look at the "spindown" problem. European, American, and Japanese satellite agencies have a number of Earth-observation missions with the objective of providing improved measurements of components of the global hydrological cycle-clouds, precipitation, soil moisture, and water vapor-from a range of operational platforms in both polar and geostationary orbits. Significant development of data assimilation methods will be necessary to make full use of both the existing and new types of observations of the water cycle. The small-scale

SUMMARYA multiple-scattering radiative transfer model for microwave radiance data assimilation in global numerical weather-prediction models is presented. The model is part of the RTTOV software package and includes forward, tangent-linear, adjoint and Jacobian models. The model is based on the Eddington approximation to radiative transfer which produces mean errors of less than 0.5 K at the targeted microwave frequencies between 10 and 200 GHz. The simplified treatment of subgrid-scale cloud cover may produce biased model calculations that show a maximum at 0.5 cloud cover and may reach several degrees K. These errors may be corrected with a simple bias correction. Linearity tests indicate that, given a screening procedure that excludes situations in which the model responds nonlinearly to input perturbations, channels near 50. 3, 19.35, 22.235 and 183.31 GHz may be used in global radiance data assimilation.