Optical characterization of OLED displays

Multispectral viewing angle and imaging characterization have been applied to different organic light‐emitting diode (OLED) displays. Angular dependence of the OLED emission is always complex because of its multilayer structure. Spectral information is also related to the geometry of Fabry–Perot‐like structure of each OLED. High‐resolution viewing angle measurements of different OLED displays are reported and compared. Multispectral viewing angle polarization properties are also reported. Imaging measurements allow to detect wavelength shift on the surface of the displays probably related to thickness non‐uniformities. Local radiance fluctuations from one pixel to the other more related to driving problems due to the dispersion of the electric properties of the driving thin‐film transistors are also detected.