Omnidirectional light emission via surface plasmon polaritons

The simulations and experiments on light emitters within a planar, metal/insulator/metal cavity demonstrate an omnidirectional resonance. This is a resonance for which the maximum decay rate enhancement in the cavity occurs at a well-defined wavelength independent of emission angle. It is shown numerically that the resonance occurs when the cavity thickness is a quarter of the surface plasmon wavelength. Experiments on a gold/blue-emitting polymer/gold cavity support this. Further simulations show that low loss omnidirectional cavities have an emission intensity that is largely independent of angle, which may find application for solid state light sources that require a broad emission cone.