Optical filters and OLEDs with narrow linewidth and low angle dispersion via strong light-matter coupling

Organic materials are good absorbers for optical filters and good emitters for OLEDs, largely due to their high oscillator strengths. However, this comes at the cost of broad spectral linewidths, which limits the usefulness of absorptive filters and restricts colour purity in displays. Interference-based structures offer narrower spectra but show an intrinsic and often substantial angle dependence. Here, we overcome these limitations by combining the concepts of absorption and interference. Introducing absorbers into a microcavity leads to a coupled polariton state that inherits the low dispersion of the material exciton and the narrow linewidth of the cavity mode and thus enables line-filters with record spectral discrimination and angular stability (e.g., FWHM 10%, FWHM <20nm, angle shift <10nm @60° tilt).