Free-space optical data transmission using wavelength-division-multiplexing with a dedicated CMOS image sensor for indoor optical wireless LAN

We have proposed a space- and wavelength-division-multiplexing (WDM) indoor optical wireless LAN system based on a custom CMOS image sensor to realize a compact, high-speed, and intelligent nodes and hub. The CMOS image sensor can detect multiple fast optical data concurrently as well as captures ordinary images from which positions of communication nodes or the hub is obtained. In this paper, with the CMOS image sensor, we demonstrate an application of WDM technique to downlinks. We fabricated a 64x64-pixel custom CMOS image sensor with 4-channel concurrent data acquisition function. Experimental results showed that the CMOS sensor received 10Mbps×3ch WDM data while capturing ordinary images.