Ballon Generali diameter of . It has been used as advertising billboard for Fortis, then from 2002 for Eutelsat. In 2008, a partnership has been signed with Banque populaire and Airparif : renamed "ballon Air de Paris", its internal illumination system changes the outer colour in real-time, according to the ambient air pollution in Paris, measured by Airparif : from green (good) to red (bad) through orange (poor). This system was completed by an independent lighting (panels light-emitting diode, visible especially at night on the lower part of the shell) stating the air quality near traffic with the same colour code. On
Superluminescent diode Superluminescent diode A superluminescent diode (SLED or SLD) is an edge-emitting semiconductor light source based on superluminescence. It combines the high power and brightness of laser diodes with the low coherence of conventional light-emitting diodes. Its emission band is 5–100 nm wide. In 1986 Dr. Gerard A. Alphonse at RCA Laboratories (now SRI International), invented the superluminescent diode. This light source was developed as a key component in the next generations of fibre optic gyroscopes, low coherence tomography for medical imaging, and external cavity tunable lasers with applications to fiber-optic communications. In 1989 the technology was transferred to GE-RCA in