Abstract: A display system in accordance with the present invention includes a display screen having a phosphor that emits light in a wavelength range from about 450 nm to about 650 nm when excited by a laser beam. The laser beam is generated by a solid-state laser having an operating wavelength range from about 330 nm to about 440 nm.

Abstract: Doped diffraction gratings for use in quantum cascade lasers and mid-infrared wavelength vertical cavity surface emitting lasers can be made by introducing periodic variations in the doping levels that result in periodic refractive index variations. Doping is typically accomplished by use of an n type dopant.

Abstract: A buried heterostructure quantum cascade laser structure uses reverse biased junction to achieve current blocking. Doping and ridge width of the structure may be adjusted to provide effective mode discrimination.

Abstract: Subwells are added to quantum wells of light emitting semiconductor structures to shift their emission wavelengths to longer wavelengths. Typical applications of the invention are to InGaAs, InGaAsSb, InP and GaN material systems, for example.

Abstract: The device is an optoelectronic device or transparent waveguide device that comprises a growth surface, a growth mask, an optical waveguide core mesa and a cladding layer. The growth mask is located on the semiconductor surface and defines an elongate growth window having a periodic grating profile. The optical waveguide core mesa is located in the growth window and has a trapezoidal cross-sectional shape. The cladding layer covers the optical waveguide core mesa and extends over at least part of the growth mask. Such devices are fabricated by providing a wafer comprising a growth surface, growing an optical waveguide core mesa on the growth surface by micro-selective area growth at a first growth temperature and covering the optical waveguide core mesa with cladding material at a second growth temperature, lower than the first growth temperature.

Abstract: A light emitting device in accordance with an embodiment of the present invention includes a first semiconductor layer of a first conductivity type having a first surface, and an active region formed overlying the first semiconductor layer. The active region includes a second semiconductor layer which is either a quantum well layer or a barrier layer. The second semiconductor layer is formed from a semiconductor alloy having a composition graded in a direction substantially perpendicular to the first surface of the first semiconductor layer. The light emitting device also includes a third semiconductor layer of a second conductivity type formed overlying the active region.

Abstract: The device is an optoelectronic device or transparent waveguide device that comprises a growth surface, a growth mask, an optical waveguide core mesa and a cladding layer. The growth mask is located on the semiconductor surface and defines an elongate growth window. The optical waveguide core mesa is located in the growth window and has a trapezoidal cross-sectional shape. The cladding layer covers the optical waveguide core mesa and extends over at least part of the growth mask. Such devices are fabricated by providing a wafer comprising a growth surface, growing an optical waveguide core mesa on the growth surface by micro-selective area growth at a first growth temperature and covering the optical waveguide core mesa with cladding material at a second growth temperature, lower than the first growth temperature.

Abstract: An optical isolator for coupling light from a first waveguide to a second waveguide is disclosed. The optical isolator utilizes a resonator coupled to the first and second optical waveguides. The resonator has a resonance at ? for light traveling from the first optical waveguide to the second optical waveguide; however, the resonator does not have a resonance at ? for light traveling from the second waveguide to the first waveguide. The resonator can use a layer of ferromagnetic material in an applied magnetic field. The magnetic field within the ferromagnetic material varies in strength and/or direction over the layer of ferromagnetic material. The magnetic field can be generated by an external magnetic field that varies over the layer of ferromagnetic material. Alternatively, the resonator can include a layer of ferromagnetic metal that overlies a portion of the layer of ferromagnetic material and a constant external magnetic field.

Abstract: A modulated light emitter having a laser and modulator constructed on a common substrate. The light emitter includes an active layer having a quantum well (QW) layer sandwiched between first and second barrier layers. The active layer includes a laser region and a modulator region connected by a waveguide. The laser region emits light when a potential is applied across the active layer in the laser region. The modulator region has a first state in which the modulator region absorbs the generated light and a second state in which the modulator region transmits the generated light. The modulator region assumes either the first or second state depending on the potential across the modulator region. The QW layer in the modulator region is under a tensile strain, which provides improved light absorption in the first state.

Abstract: An improved tunnel junction structure and a VCSEL that uses this structure is disclosed. The tunnel junction includes first, second, and third layers that include materials of the InP family of materials. The first layer is doped with n-type dopant species to a concentration of 1019 dopant atoms per cm3 or greater. The second layer is doped with Zn to a similar concentration and is in contact with the first layer. The interface between the first and second layers forms a tunnel junction. The third layer includes a material that retards the diffusion of Zn out of the second layer. The third layer preferably includes undoped AlInAs. The tunnel junction structure of the present invention can be utilized in a VCSEL having an active layer between first and second mirrors that are both constructed from n-type semiconductor layers.

Abstract: A modulated light emitter having a laser and modulator constructed on a common substrate. The light emitter includes an active layer having a quantum well (QW) layer sandwiched between first and second barrier layers. The active layer includes a laser region and a modulator region connected by a waveguide. The laser region emits light when a potential is applied across the active layer in the laser region. The modulator region has a first state in which the modulator region absorbs the generated light and a second state in which the modulator region transmits the generated light. The modulator region assumes either the first or second state depending on the potential across the modulator region. The QW layer in the modulator region is under a tensile strain, which provides improved light absorption in the first state.

Abstract: A semiconductor laser. The semiconductor laser has an indium-phosphide (InP) non-(100) substrate and an active region grown above the substrate. In so doing, embodiments of the present invention provide for the formation of a semiconductor laser with good morphology and low contamination while allowing the use of wide process windows. Opening the process window greatly simplifies the formation process, leads to more consistent results, and achieves better yields under mass production.