In this paper, we describe a new type of digital-to-analog converter (DAC) for optical wireless communication. Conversion occurs in the optical rather than the electrical domain. The overall intensity of the light transmitted by an array of light-emitting diodes (LEDs) is varied by changing the number of LEDs that are switched on. A number of different structures are described, and their compatibility with light dimming and overall energy efficiency are discussed. The linearity of the new DAC depends on the geometry of the system and on the variability in light output between individual LEDs.