There are two ways to attain near-perfect light extraction from a spontaneous light emitter, namely the use of a fully transparent structure or the employment of an omni-directional mirror reflecting light irrespective of wavelength and angle of incidence. Metallic layers are capable of reflecting light over a wide range of wavelengths and incident angles. The high-reflectivity band is limited to frequencies below the plasma frequency of the free electron gas. However, electron oscillations induced by the incident light waves not only result in reflection but also in absorption caused by electron–phonon scattering.
© 2003 Optical Society of AmericaPDF Article