A quantum dot laser includes a GaAs substrate, a quantum dot active layer which has a barrier layer of GaAs and quantum dots, a GaAs waveguide core layer which is joined to the quantum dot active layer, and a lower cladding layer and an upper cladding layer which sandwich the quantum dot active layer and the GaAs waveguide core layer. The GaAs waveguide core layer extends from a front end of the quantum dot active layer and has a thickness which gradually decreases in a direction to depart from the front end of the quantum dot active layer, a refractive index of a first cladding layer is higher than a refractive index of a second cladding layer. With this structure, expansion of the optical mode diameter that is more than necessary is inhibited to prevent leakage of light, thereby obtaining sufficient optical output.

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 semiconductor device employs an epitaxial layer arrangement including a first ohmic contact layer and first modulation doped quantum well structure disposed above the first ohmic contact layer. The first ohmic contact layer has a first doping type, and the first modulation doped quantum well structure has a modulation doped layer of a second doping type. At least one isolation ion implant region is provided that extends through the first ohmic contact layer. The at least one isolation ion implant region can include oxygen ions. The at least one isolation ion implant region can define a region that is substantially free of charge carriers in order to reduce a characteristic capacitance of the device. A variety of high performance transistor devices (e.g., HFET and BICFETs) and optoelectronic devices can employ this device structure. Other aspects of wavelength-tunable microresonantors and related semiconductor fabrication methodologies are also described and claimed.

A semiconductor light-emitting element includes a semiconductor stacked layer, an electrode, and an electrode. The semiconductor stacked layer includes an active layer and a phase modulation layer. The phase modulation layer includes a plurality of phase modulation areas. Each of the plurality of phase modulation areas includes a basic region which has a first refractive index and a plurality of different-refractive-index regions which have a second refractive index different from the first refractive index and which are distributed in a two-dimensional shape. The electrode includes a plurality of electrode parts overlapping the plurality of phase modulation areas when seen in a stacking direction of the semiconductor stacked layer. The plurality of electrode parts are electrically isolated from each other. Laser light oscillating in each of the plurality of phase modulation areas is applied to a common irradiation area as light images according to arrangement of the plurality of different-refractive-index regions.

A semiconductor strip laser and a semiconductor component are disclosed. In embodiments the laser includes a first semiconductor region of a first conductivity type of a semiconductor body, a second semiconductor region of a second different conductivity type of the semiconductor body, at least one active zone of the semiconductor body configured to generate laser radiation between the first and second semiconductor regions. The laser further includes a strip waveguide formed at least in the second semiconductor region and providing a one-dimensional wave guidance along a waveguide direction of the laser radiation generated in the active zone during operation, a first electric contact on the first semiconductor region, a second electric contact on the second semiconductor region and at least one heat spreader dimensionally stably connected to the semiconductor body at least up to a temperature of 220 C., and having an average thermal conductivity of at least 50 W/m.Math.K.

In an example, the present invention provides a method for fabricating a light emitting device configured as a Group III-nitride based laser device. The method also includes forming a gallium containing epitaxial material overlying the surface region of a substrate member. The method includes forming a p-type (Al,In,Ga)N waveguiding material overlying the gallium containing epitaxial material under a predetermined process condition. The method includes maintaining the predetermined process condition such that an environment surrounding a growth of the p-type (Al,In,Ga)N waveguide material is substantially a molecular N.sub.2 rich gas environment. The method includes maintaining a temperature ranging from 725 C to 925 C during the formation of the p-type (Al,In,Ga)N waveguide material, although there may be variations. In an example, the predetermined process condition is substantially free from molecular H.sub.2 gas.

A semiconductor device according to the present disclosure includes a main part that includes a semiconductor substrate, a first cladding layer provided on the semiconductor substrate, an active layer provided on the first cladding layer, and a second cladding layer provided on the active layer, and in which a flat part and a mesa part are formed, the mesa part including the active layer and a first embedded layer covering a top surface of the flat part and a side surface of the mesa part, wherein the first embedded layer has a projecting part on a top surface of a portion provided in a region within a height of the mesa part from a boundary between the mesa part and the flat part in the top surface of the flat part.

A laser diode includes a substrate, an epitaxial structure, an electrode contacting layer and an optical cladding layer. The epitaxial structure is disposed on the substrate, and is formed with a ridge structure opposite to the substrate. The electrode contacting layer is disposed on a top surface of the ridge structure. The optical cladding layer has a refractive index smaller than that of the electrode contacting layer. The optical cladding layer includes a first cladding portion which covers side walls of the ridge structure, and a second cladding portion which is disposed on a portion of the top surface of the ridge structure. A method for manufacturing the abovementioned laser diode is also disclosed.

An optical semiconductor chip of the present disclosure includes a high frequency line between an electrode pad receiving a modulation signal and a modulation electrode on the optical waveguide constituting a laser. The depletion layer capacitance generated in an active layer of the optical waveguide is cancelled by an inductance component of the high frequency line. When a portion directly below the high frequency line is embedded with a low-dielectric-constant material or is made hollow, the parasitic capacitance is further reduced. The high frequency line may have a zigzag shape as well as a linear shape. The electrode pad on the optical semiconductor chip can be connected to other substrates including RF lines for modulation signal input by bumps or wire bonding.

A semiconductor laser device includes a first conductivity type cladding layer having a refractive index n.sub.c1, a first conductivity type side optical guide layer, an active layer, a second conductivity type side optical guide layer, and a second conductivity type cladding layer of n.sub.c2 laminated in order on a first conductivity type semiconductor substrate, wherein an oscillation wavelength is , a first conductivity type low refractive index layer of n.sub.1 lower than n.sub.c1 having a thickness of d.sub.1 is provided between the first conductivity type side optical guide layer and the first conductivity type cladding layer, a second conductivity type low refractive index layer of n.sub.2 lower than n.sub.c2 having a thickness of d.sub.2 is provided between the second conductivity type side optical guide layer and the second conductivity type cladding layer, and a condition of a normalization frequency v.sub.2>v.sub.1 is satisfied.