A electro-absorption optical modulator includes a multiple quantum well composed of a plurality of layers including a plurality of quantum well layers and a plurality of barrier layers that are alternately stacked, the plurality of quantum well layers and the plurality of barrier layers including an acceptor and a donor; a p-type semiconductor layer in contact with an uppermost layer of the plurality of layers; and an n-type semiconductor layer in contact with a lowermost layer of the plurality of layers, the multiple quantum well being 10% or more and 150% or less of the p-type semiconductor layer in a p-type carrier concentration, and in the multiple quantum well, an effective carrier concentration which corresponds to a difference between the p-type carrier concentration and an n-type carrier concentration is 10% or less of the p-type carrier concentration of the multiple quantum well.

A modulation doped semiconductor laser includes a multiple quantum well composed of a plurality of layers including a plurality of first layers and a plurality of second layers stacked alternately and including an acceptor and a donor; a p-type semiconductor layer in contact with an uppermost layer of the plurality of layers; and an n-type semiconductor layer in contact with a lowermost layer of the plurality of layers, the plurality of first layers including the acceptor so that a p-type carrier concentration is 10% or more and 150% or less of the p-type semiconductor layer, the plurality of second layers containing the acceptor so that the p-type carrier concentration is 10% or more and 150% or less of the p-type semiconductor layer, the plurality of second layers containing the donor, and an effective carrier concentration corresponding to a difference between the p-type carrier concentration and an n-type carrier concentration is 10% or less of the p-type carrier concentration of the plurality of second layers.

An optoelectronic device configured for improved light extraction through a region of the device other than the substrate is described. A group III nitride semiconductor layer of a first polarity is located on the substrate and an active region can be located on the group III nitride semiconductor layer. A group III nitride semiconductor layer of a second polarity, different from the first polarity, can located adjacent to the active region. A first contact can directly contact the group III nitride semiconductor layer of the first polarity and a second contact can directly contact the group III nitride semiconductor layer of the second polarity. Each of the first and second contacts can include a plurality of openings extending entirely there through and the first and second contacts can form a photonic crystal structure. Some or all of the group III nitride semiconductor layers can be located in nanostructures.

A method for preparing an erbium (Er)- or erbium oxygen (Er/O)-doped silicon-based luminescent material emitting a communication band at room temperature. The method comprising the following steps: (a) doping a single crystalline silicon wafer with erbium ion implantation or co-doping the single crystalline silicon wafer with erbium ion and oxygen ion implantation simultaneously to obtain an Er- or Er/O-doped silicon wafer, wherein the single crystalline silicon wafer is a silicon wafer with a germanium epitaxial layer, or an SOI silicon wafer with silicon on an insulating layer or other silicon-based wafers; and (b) subjecting the Er- or Er/O-doped silicon wafer to a deep-cooling annealing treatment, the deep-cooling annealing treatment includes a temperature increasing process and a rapid cooling process.

Disclosed in an embodiment is a semiconductor device comprising a semiconductor structure, which comprises a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer, wherein: the first conductive semiconductor layer comprises a first super lattice layer comprising a plurality of first sub layers and a plurality of second sub layers, the first and second sub layers being alternately arranged; the semiconductor structure emits ions of indium, aluminum, and a first and second dopant during a primary ion irradiation; the intensity of indium ions emitted from the active layer includes a maximum indium intensity peak; the doping concentration of the first dopant emitted from the first conductive semiconductor layer includes a maximum concentration peak; the maximum indium intensity peak is disposed to be spaced from the maximum concentration peak in a first direction; the intensity of indium ions emitted from the plurality of first sub layers has a plurality of first indium intensity peaks; the doping concentration of the first dopant emitted from the plurality of first sub layers has a plurality of first concentration peaks; and the plurality of first indium intensity peaks and the plurality of first concentration peaks are disposed between the maximum indium intensity peak and the maximum concentration peak.

An optoelectronic device configured for improved light extraction through a region of the device other than the substrate is described. A group III nitride semiconductor layer of a first polarity is located on the substrate and an active region can be located on the group III nitride semiconductor layer. A group III nitride semiconductor layer of a second polarity, different from the first polarity, can located adjacent to the active region. A first contact can directly contact the group III nitride semiconductor layer of the first polarity and a second contact can directly contact the group III nitride semiconductor layer of the second polarity. Each of the first and second contacts can include a plurality of openings extending entirely there through and the first and second contacts can form a photonic crystal structure. Some or all of the group III nitride semiconductor layers can be located in nanostructures.

A germanium waveguide is formed from a P-type silicon substrate that is coated with a heavily-doped N-type germanium layer and a first N-type doped silicon layer. Trenches are etched into the silicon substrate to form a stack of a substrate strip, a germanium strip, and a first silicon strip. This structure is then coated with a silicon nitride layer.

Embodiments of the invention include a III-nitride light emitting layer disposed between an n-type region and a p-type region, a III-nitride layer including a nanopipe defect, and a nanopipe terminating layer disposed between the III-nitride light emitting layer and the III-nitride layer comprising a nanopipe defect. The nanopipe terminates in the nanopipe terminating layer.

A monolithic integrated semiconductor random laser composed of a gain region and random feedback region, comprising: a substrate, a lower confinement layer on the substrate, an active layer on the lower confinement layer, an upper confinement layer on the active layer, a strip-shaped waveguide layer longitudinally made in middle of the upper confinement layer, a P.sup.+ electrode layer divided into two segments by an isolation groove and made on the waveguide layer, and an N.sup.+ electrode layer on a back face of the lower confinement layer. The two segments of the P.sup.+ electrode layer correspond respectively to the gain region and the random feedback region. The random feedback region uses a doped waveguide to randomly feed back light emitted and amplified by the gain region. As a result, random laser is emitted. Frequency and intensity of laser emitted by semiconductor laser are random, and a monolithic integration structure is used, making semiconductor laser be light, small, stable in performance, and strong in integration.

A semiconductor laser includes an active layer which is provided between the p-type semiconductor region and the n-type semiconductor region and has a type II quantum well structure. The type II quantum well structure includes a well layer made of a III-V compound semiconductor and a plurality of barrier layers. The well layer includes a first region and a second region, the first region having a low potential for electrons in the well layer and a high potential for holes in the well layer, the second region having a high potential for electrons in the well layer and a low potential for holes in the well layer. The first region and the second region of the well layer are arranged in a direction from one of the barrier layers to another of the barrier layers.