| abstract |
A device for a light detection system includes an electroluminescent layer stack on a transparent member, such as a glass substrate, with at least one layer of the layer stack being patterned to define first and second electroluminescent regions spaced apart by a transparent light collection path for passage of backreflected light. The layer stack includes first and second electrode layers on opposed sides of one or more active layers. In one embodiment, the second electrode layer is the only layer that is patterned to define the light collection path. In this embodiment, the other layers extend continuously across the light collection path. In another embodiment, all of the layers are patterned to form a gap between the first and second electroluminescent regions. The layer stack is hermetically sealed to protect the active layer or layers from atmosphere-induced degradation. An illumination collector is aligned with the light collection path to receive light that is backreflected from a surface of interest through the light collection path. The illumination collector may be an optical arrangement, a photodetector, or both. In the preferred embodiment, the electroluminescent layer stack is an organic light-emitting source. |