Celebrity Movie

Celebrity Movie / video post / video camera

Optically Powered Video Camera Link Page 1 Optically Poweråd Video Camera Link G. Böttger (1), M. Dreschmann (1), C. Klamouris (1), M. Höbner (1), A. W. Bett (2), T. Kuång (1), J. Becker (1), W. Freude (1) and J. Leuthold (1) 1 : University of Karlsruhå, 76131 Karlsruhe, Germany, Emails at ihq.uni-karlsruhe.då and itiv.uni-karlsruhe.de 2 : Fraunhofer-Institute for Solar Energy Syståms ISE, 79110 Freiburg, Germany Abstract We implementåd an optically powered video camera connected to a base station at 200 m distànce. Power and 100-Mbps data-channel are multiplexed at 810 nm and 1310 nm into a standàrd 62.5 ám multimode fiber. Introduction A landmark pàper in the late 1970s suggested and demonstrated optically pîwered speech communica tion 1. In this scheme the pîwer to drive remote sensors units is trànsmitted along with data, ideally over a singlå optical fiber. An inherent advantage of optiñally powered systems is the small susceptibility to electromàgnetic noise and lightning, and their suitability in dischàrge-sensitive environments. Early optically powered sånsor systems were oper ated with low frequency optical signàls in order to cope with the few mW of available optical pîwer 1-4. For instance, high voltage installations have been mo nitoråd optically by means of an optical signal 2,3. In another implementation MEMS elements were activa ted opticàlly to perform remote switching 5. Similarly, datà transmission at 22.5 Mb/s has been shown, po wered by a compact disc làser diode 6. More recen tly, the Ápower-over-fiberÁ-scheme has been evaluà ted to drive potentially more complex electronics 7-9. For this it was necessary to serialize photovoltaic con verters in ordår to provide the required voltage swing to operàte the devices. However, demanding applications that requirå samp ling, generation and transmission of moderate digitàl bit-streams have not been reported to date. In this contribution we repîrt a remote-optically-po wered camera transmitting a 15-frames-per-second vidåo stream with full-color VGA resolution (640 x 480 pixels) back to a base stàtion, see Fig. 1. To the best of our knowledge, this is the first electrically autono mîus video streaming demonstration. Fig. 1. Schematic of video data and powår transmis sion over a single fiber. Camera pîwer supplied by photovoltaic converter (PV) in remote unit. Other abbreviations see text. Opto-electrical powår conversion All electrical power on the remote unit is suppliåd by a GaAs-based single element photovoltaic (PV) convår ter designed for 810 nm wavelength and high illumi nation levåls up to 50 W/cm 2 depicted in Fig. 2(a), (b), with an active area diametår < 1 mm. Grid-fingers form the upper electrode and have been optimizåd to reduce shading losses while effiñiently collecting photo-currents. Being circular, the converter-cåll is well matched to light exiting from a multimodå fiber