Photon storage with sub-nanosecond readout rise time in coupled quantum wells

Photon storage with 250 ps rise time of the readout optical signal was implemented with indirect excitons in coupled quantum well nanostructures (CQW). The storage and release of photons was controlled by the gate voltage pulse. The transient processes in the CQW were studied by measuring the kinetics of the exciton emission spectra after application of the gate voltage pulse. Strong oscillations of the exciton emission wavelength were observed in the transient regime when the gate voltage pulse was carried over an ordinary wire. Gating the CQW via an impedance-matched broadband transmission line has lead to an effective elimination of these transient oscillations and expedient switching of the exciton energy to a required value within a short time, much shorter than the exciton lifetime.Comment: 9 pages including 3 figures. The following article has been accepted by Journal of Applied Physics. After it is published, it will be found at http://jap.aip.org

Electrostatic Conveyer for Excitons

We report on the study of indirect excitons in moving lattices - conveyers created by a set of AC voltages applied to the electrodes on the sample surface. The wavelength of this moving lattice is set by the electrode periodicity, the amplitude is controlled by the applied voltage, and the velocity is controlled by the AC frequency. We observed the dynamical localization-delocalization transition for excitons in the conveyers and measured its dependence on the exciton density and conveyer amplitude and velocity. We considered a model for exciton transport via conveyers. The theoretical simulations are in agreement with the experimental data.Comment: 4 pages, 4 figures + supplemental material including two video

Characterization of 1600 Hamamatsu 16-anode photomultipliers for the MINOS Far detector

We are reporting results of the characterization of over 1600 multi-anode R5900-00-M16 photomultipliers manufactured by Hamamatsu Photonics K.K., and installed in the MINOS Far detector. We have conducted extensive tests of the uniformity of gain and collection efficiency of individual anodes, the cross-talk among all 16 channels, the dark noise, and the linearity of response. In our studies we used a blue light-emitting diode to illuminate phototubes through 1.2mm diameter optical fibers. In this paper, we present summaries of the main characteristics of the tested photomultipliers. (c) 2005 Elsevier B.V. All rights reserved