EFFECT OF SIDEWALL REFLECTOR ON CURRENT VERSUS LIGHT OUTPUT IN A PNPNVERTICAL-TO-SURFACE TRANSMISSION ELECTROPHOTONIC DEVICE WITH A VERTICAL-CAVITY

We experimentally study the effect of a sidewall reflector on current versus light-output characteristics in a pnpn vertical-to-surface tran smission electrophotonic device with a vertical cavity. The distribute d Bragg reflectors that form the vertical cavity for laser oscillation and the sidewall reflector retain spontaneously emitted photons in th e optical cavity, and only the photons that have the resonance wavelen gth of the vertical cavity are emitted from the optical cavity. As a r esult, spontaneously emitted photons are absorbed and the carriers are regenerated. That is, the injected carriers are converted to light, a nd spontaneous emission is reconverted to carriers. As a result of pho ton recycling of spontaneous emission, threshold reduction is expected . Threshold reduction by at least a factor of 4 is obtained with a dev ice that has the sidewall reflector.