The new LED-based luminaires will be
omnipresent a few years from now. Besides their
original lighting function, their light can be modulated
at high speed. In this way, we can realize
significantly higher data rates over moderate distanceswhich is the focus of this article. For
higher speed (>10 Gb/s) or longer distances,
laser diodes, as typically applied in outdoor free
space optical (FSO) communications, appear to
be the better choice. In both cases, PIN or more
sensitive avalanche photodiodes (APDs) are
used as receivers.