High radiance Burrus LED's with integral 45° mirrors

Modifications have been made to the Burrus LED structure to enable increases in the total light output to be obtained. Incorporation of a circumferential 45° mirror in the active layer of the GaAs/ GaAlAs double heterostructure, surrounding the light-emitting region, redirects the (normally lost) light confined in the active layer towards the emitting surface. In addition to increased light output, these devices have markedly more linear (≃ 14-dB second-harmonic reduction)light-current characteristics than normal Burrus LED's. For devices with thin (0.2-µm) lightly doped (
N_{A} \simeq 5 \times 10^{17}
cm
^-3
) active layers a significant in-plane superluminescence contribution to the light output is found. A theoretical model has been developed which provides an adequate description of the observed device characteristics and enables predictions to be made for further device optimization.