Organic light-emitting diodes (OLEDs) are scalable area light sources which can be designed to emit a variety of spectral distributions in the visible part of the electromagnetic spectrum. Typically, the emission pattern is close to be of Lambertian distribution for optimized devices. Various applications scenarios can be conceived, where OLEDs with variable angular beam shapes can be of high interest. In this presentation, we discuss the possibility to design tandem OLEDs that sport a forward and a sideward emitting unit, respectively. This design together with a pulse-width modulation-based driving scheme allows to continuously alter the emitted beam shape. This presentation focuses on the optical design of such a complex cavity and the details of the driving scheme utilized.
© 2017 Optical Society of AmericaPDF Article