Abstract: Semiconductor devices comprising a semiconductor edge filter, a first light absorbing region overlying the semiconductor edge filter and a second light absorbing region underlying the semiconductor edge filter are disclosed. The semiconductor edge filter has a high reflectivity over a first wavelength range absorbed by the overlying light absorbing region and a high transmission over a second wavelength range absorbed by the underlying light absorbing region.

Abstract: A VCSEL device having non-coaxial-with-one-another apertures and/or rotationally asymmetric apertures formed in layer(s) of the VCSEL structure to define more than one spatial mode in a light output in operation of the device. An array of such VCSEL devices configured to have different spatial modes at the output of different constituent VCSEL devices. Spatial asymmetry of structure of the constituent VCSEL devices and, therefore, arrays of VCSEL devices causes the overall light output to form an irregular grid of output spots of light. When the VCSEL array is equipped with an appropriate lens array, the spatial components of the light output of the VCSEL array are caused to overlap in the far at the imaging plane in a multiple spatial (and spectral) mode fashion, thereby reducing speckle in imaging applications.

Abstract: An electronic device having a display with an infrared component (such as a camera, a light source) behind the display. The layer of the display is transparent to infrared light at which the infrared component operates. Infrared sensing functions, when implemented by the component, may be accomplished by transmission of infrared light through the layer of the display, thereby removing the conventional need for cut-outs or holes in the display plane and maximizing the display area.

Abstract: Semiconductor structures including optically-transparent metamorphic buffer regions, devices employing such structures, and methods of fabrication. The optically-transparent metamorphic buffer is grown to provide a lattice constant transition between a smaller lattice constant and a larger lattice constant (or vice-versa), allowing materials with two different lattice constants to be monolithically integrated. Such buffer layer may include at least two elements from group V of the periodic table. The optically-transparent metamorphic buffer region may include digital-alloy superlattice structure (s) to confine material defects to the metamorphic buffer layer, and improve electrical properties of the metamorphic buffer layer, thereby improving the electronic properties of electronic devices such as optoelectronic devices and photovoltaic cells. Photonic devices such as solar cells and optical detectors containing such semiconductor structures.

Abstract: Semiconductor devices comprising a semiconductor edge filter, a first light absorbing region overlying the semiconductor edge filter and a second light absorbing region underlying the semiconductor edge filter are disclosed. The semiconductor edge filter has a high reflectivity over a first wavelength range absorbed by the overlying light absorbing region and a high transmission over a second wavelength range absorbed by the underlying light absorbing region.

Abstract: An electronic device having a display with an infrared component (such as a camera, a light source) behind the display. The layer of the display is transparent to infrared light at which the infrared component operates. Infrared sensing functions, when implemented by the component, may be accomplished by transmission of infrared light through the layer of the display, thereby removing the conventional need for cut-outs or holes in the display plane and maximizing the display area.

Abstract: A stacked superluminescent light-emitting diode having multiple active regions coupled together using and via tunnel junctions. The material compositions of each of the active regions (corresponding quantum wells and/or barriers) differ from one another to provide a controlled different light emission at wavelength (and/or wavelength range) for each junction. In operation of the device, the spectral width of the aggregate light output generated by different junctions is defined by all the junctions, thereby producing a spectrally-broader emission than that of any single, separately taken junction within the device. Thus, the device is configured to operate as a broadband infrared light source.

Abstract: An electronic device having a display with an infrared component (such as a camera, a light source) behind the display. The layer of the display is transparent to infrared light at which the infrared component operates. Infrared sensing functions, when implemented by the component, may be accomplished by transmission of infrared light through the layer of the display, thereby removing the conventional need for cut-outs or holes in the display plane and maximizing the display area.

Abstract: Semiconductor light absorption devices such as multi junction photovoltaic cells include a chirped distributed Bragg reflector beneath a junction. The chirped distributed Bragg reflector provides a high reflectivity over a broad range of wavelengths and has improved angular tolerance so as to provide increased absorption within an overlying junction over a broader range of wavelengths and incident angles.

Abstract: Structures and methods for electronic devices with improved conductive regions are provided. The conductive region may include digital alloy superlattice structures, which allow higher doping levels to be achieved than for a bulk (random) alloy with the same average composition. Furthermore, the superlattice structures may improve the resistivity of the region, improving the current spreading of the region and hence the electronic properties of electronic devices such as optoelectronic devices.

Abstract: Structures and methods for electronic devices with improved conductive regions are provided. The conductive region may include digital alloy superlattice structures, which allow higher doping levels to be achieved than for a bulk (random) alloy with the same average composition. Furthermore, the superlattice structures may improve the resistivity of the region, improving the current spreading of the region and hence the electronic properties of electronic devices such as optoelectronic devices.

Abstract: The invention discloses improved structures of light-processing (e.g. light-emitting and light-absorbing/sensing) devices, in particular Vertical Cavity Surface Emitting Lasers (VCSELs), such as may find use in telecommunications applications. The disclosed VSCAL devices and production methods provide for an active region having a quantum well structure grown on GaAs-containing substrates, thus providing processing compatibility for light having wavelength in the range 1.0 to 1.6 ?m. The active region structure combines strain-compensating barriers with different band alignments in the quantum wells to achieve a long emission wavelength while at the same time decreasing the strain in the structure. The improved functioning of the devices disclosed results from building them with multicomponent alloy layers having a large number of constituents.

Abstract: A vertical cavity surface emitting laser device (10) has a discontinuity (11) formed within the body of the device. When the device is in use, the direction of polarization of light emitted from the device is substantially aligned with a boundary of the discontinuity.

Abstract: A compound semiconductor device is provided that includes a substrate and an active region disposed above the substrate. The active region includes at least two different pseudomorphic layers, the first layer having the form InxGa1−xPyAszSb1−y−z, and the second layer having the form InqGa1−qPrAssSb1−r−s. The first layer includes at least In, Ga, and As, and the second layer includes at least Ga, As, and Sb. It is preferable for the substrate to be GaAs or AlpGa1−pAs (0<p<1), or to have a lattice constant close to or equal to that of GaA For the first layer, it is preferable if x is between 0.05 and 0.7, y is between 0 and 0,35, z is between 0.45 and 1, and 1−y−z is between 0 and 0.25. For the second layer, it is preferable if q is between 0 and 0.25 and 1−r−s is between 0.25 and 1.

Abstract: In the present invention, there is provided an optical device comprising a multimode interference (MMI) optical waveguide section having a number of electrodes extending over at least a portion of the length of the MMI section, where the application of an electrical bias to an electrode causes a local change in effective refractive index of the MMI section, thereby causing light preferentially to propagate along a path defined by the configuration of said electrode. Whereas current injection has been demonstrated in the prior art, the present invention operates by the application of a reverse bias electric field, via suitably shaped electrodes, to locally increase the reflective index within part of the device. Thus the electrodes on the device are used to create new wave guiding paths, rather than to minimise mode coupling to crossover states, as is the case with prior art devices. The shape and extent of the induced waveguides can be controlled by the shape of the electrodes.