A semiconductor device includes a substrate, a buffer layer disposed on the substrate, a barrier layer disposed on the buffer layer, a source, a drain, and a gate stack. The source, the drain, and the gate stack are disposed on the barrier layer. The gate stack includes a first epitaxial layer on the barrier layer, a second epitaxial layer on the first epitaxial layer, and a third epitaxial layer on the second epitaxial layer. The semiconductor device further includes a gate disposed on the gate stack.

A light-emitting component includes a light-emitting element, a driving thyristor, and a light-absorbing layer. The light-emitting element emits light of a predetermined wavelength. The driving thyristor causes the light-emitting element to emit light or causes an amount of light emitted by the light-emitting element to increase, upon entering an on-state. The light-absorbing layer is disposed between the light-emitting element and the driving thyristor such that the light-emitting element and the driving thyristor are stacked, and absorbs light emitted by the driving thyristor.

A light-emitting thyristor includes a first semiconductor layer of a first conductivity type; a second semiconductor layer of a second conductivity type arranged adjacent to the first semiconductor layer; a third semiconductor layer of the first conductivity type arranged adjacent to the second semiconductor layer; and a fourth semiconductor layer of the second conductivity type arranged adjacent to the third semiconductor layer. The first semiconductor layer includes an active layer adjacent to the second semiconductor layer, the second semiconductor layer includes a first layer adjacent to the active layer and a second layer arranged between the first layer and the third semiconductor layer, and the first layer has a band gap wider than a band gap of the active layer and a band gap of the second layer.

A split electrode vertical cavity optical device includes an n-type ohmic contact layer, first through fifth ion implant regions, cathode and anode electrodes, first and second injector terminals, and p and n type modulation doped quantum well structures. The cathode electrode and the first and second ion implant regions are formed on the n-type ohmic contact layer. The third ion implant region is formed on the first ion implant region and contacts the p-type modulation doped QW structure. The fourth ion implant region encompasses the n-type modulation doped QW structure. The first and second injector terminals are formed on the third and fourth ion implant regions, respectively. The fifth ion implant region is formed above the n-type modulation doped QW structure and the anode electrode is formed above the fifth ion implant region.

A light-emitting thyristor includes a first semiconductor layer of a first conductivity type; a second semiconductor layer of a second conductivity type arranged adjacent to the first semiconductor layer; a third semiconductor layer of the first conductivity type arranged adjacent to the second semiconductor layer; and a fourth semiconductor layer of the second conductivity type arranged adjacent to the third semiconductor layer. The first semiconductor layer includes an active layer adjacent to the second semiconductor layer, the second semiconductor layer includes a first layer adjacent to the active layer and a second layer arranged between the first layer and the third semiconductor layer, and the first layer has a band gap wider than a band gap of the active layer and a band gap of the second layer.

A Dual-wavelength hybrid (DWH) device includes an n-type ohmic contact layer, cathode and anode terminal electrodes, first and second injector terminal electrodes, p-type and n-type modulation doped QW structures, and first through sixth ion implant regions. The first injector terminal electrode is formed on the third ion implant region that contacts the p-type modulation doped QW structure and the second injector terminal electrode is formed on the fourth ion implant region that contacts the n-type modulation doped QW structure. The DWH device operates in at least one of a vertical cavity mode and a whispering gallery mode. In the vertical cavity mode, the DWH device converts an in-plane optical mode signal to a vertical optical mode signal, whereas in the whispering gallery mode the DWH device converts a vertical optical mode signal to an in-plane optical mode signal.

A light-emitting component includes a substrate, a light-emitting element, a thyristor, and a light-transmission reduction layer. The light-emitting element is disposed on the substrate. The thyristor causes the light-emitting element to emit light or causes an amount of light emitted by the light-emitting element to increase, upon entering an on-state. The light-transmission reduction layer is disposed between the light-emitting element and the thyristor such that the light-emitting element and the thyristor are stacked, and suppresses light emitted by the thyristor from passing therethrough.

A layered structure includes a thyristor and a light-emitting element. The thyristor at least includes four layers. The four layers are an anode layer, a first gate layer, a second gate layer, and a cathode layer arranged in this order. The light-emitting element is disposed such that the light-emitting element and the thyristor are connected in series. The thyristor includes a semiconductor layer having a bandgap energy smaller than bandgap energies of the four layers.

A light-emitting component includes a light-emitting element, a thyristor, and a light-absorbing layer. The thyristor includes a semiconductor layer having a bandgap energy smaller than or equal to a bandgap energy equivalent to a wavelength of light emitted by the light-emitting element. The thyristor causes the light-emitting element to emit light or causes an amount of light emitted by the light-emitting element to increase, upon entering an on-state. The light-absorbing layer is disposed between the light-emitting element and the thyristor such that the light-emitting element and the thyristor are stacked. The light-absorbing layer absorbs the light emitted by the light-emitting element.

A light-emitting component includes a light-emitting element, a thyristor, and a light-absorbing layer. The thyristor includes a semiconductor layer having a bandgap energy smaller than or equal to a bandgap energy equivalent to a wavelength of light emitted by the light-emitting element. The thyristor causes the light-emitting element to emit light or causes an amount of light emitted by the light-emitting element to increase, upon entering an on-state. The light-absorbing layer is disposed between the light-emitting element and the thyristor such that the light-emitting element and the thyristor are stacked. The light-absorbing layer absorbs the light emitted by the light-emitting element.