Abstract: A semiconductor apparatus for propagating light in a preferred direction which comprises, in succession, a substrate, a first emitter region, a first carrier confinement region, a first internal heterojunction barrier, a first base region, a second base region, a second internal heterojunction barrier, a second carrier confinement region, and a second emitter region, wherein portions of the first emitter region and the second base region are of one conductivity type and portions of the second emitter region and the first base region are of the opposite conductivity type, wherein the first and second emitter regions, the first and second internal heterojunction barriers and the first and second base regions together define a single optical cavity in the directions perpendicular to the preferred direction of light propagation, and electrodes are provided for applying an electrical current which flows through the semiconductor apparatus.

Abstract: A semiconductor apparatus for propagating light in a preferred direction which comprises, in succession, a substrate, a first emitter region, a first carrier confinement region, a first internal heterojunction barrier, a first base region, a second base region, a second internal heterojunction barrier, a second carrier confinement region, and a second emitter region, wherein portions of the first emitter region and the second base region are of one conductivity type and portions of the second emitter region and the first base region are of the opposite conductivity type, wherein the first and second emitter regions, the first and second internal heterojunction barriers and the first and second base regions together define a single optical cavity in the directions perpendicular to the preferred direction of light propagation, and electrodes are provided for applying an electrical current which flows through the semiconductor apparatus.