Abstract: In one embodiment, a server creates a reproduction environment of a particular condition of a particular device, the reproduction environment having a device under test (DUT) representative of the particular device, and also being seeded with features regarding the particular condition. The server generates a plurality of models for reaching a target state of the particular condition, each of the plurality of models having differing actions. According to the techniques herein, the server then iteratively refines a minimal model based on the actions of the plurality of models and whether those actions during testing of the DUT get closer to or further from the target state. In response to determining that the minimal model can no longer be further refined during the iterative refining, the server then stores the minimal model as a solution model indicating a given minimal set and order of actions required to reach the target state.

Abstract: In one embodiment, a server creates a reproduction environment of a particular condition of a particular device, the reproduction environment having a device under test (DUT) representative of the particular device, and also being seeded with features regarding the particular condition. The server generates a plurality of models for reaching a target state of the particular condition, each of the plurality of models having differing actions. According to the techniques herein, the server then iteratively refines a minimal model based on the actions of the plurality of models and whether those actions during testing of the DUT get closer to or further from the target state. In response to determining that the minimal model can no longer be further refined during the iterative refining, the server then stores the minimal model as a solution model indicating a given minimal set and order of actions required to reach the target state.

Abstract: A method of generating radiation comprises: manufacturing a structure comprising a substrate supporting a layer of InGaAs, InGaAsP, or InGaAlAs material doped with a dopant, said manufacturing comprising growing said layer such that said dopant is incorporated in said layer during growth of the layer; illuminating a portion of a surface of the structure with radiation having photon energies greater than or equal to a band gap of the doped InGaAs, InGaAsP, or InGaAlAs material so as to create electron-hole pairs in the layer of doped material; and accelerating the electrons and holes of said pairs with an electric field so as to generate radiation. In certain embodiments the dopant is Fe. Corresponding radiation detecting apparatus, spectroscopy systems, and antennas are described.

Abstract: A method of generating radiation comprises: manufacturing a structure comprising a substrate supporting a layer of InGaAs, InGaAsP, or InGaAlAs material doped with a dopant, said manufacturing comprising growing said layer such that said dopant is incorporated in said layer during growth of the layer; illuminating a portion of a surface of the structure with radiation having photon energies greater than or equal to a band gap of the doped InGaAs, InGaAsP, or InGaAlAs material so as to create electron-hole pairs in the layer of doped material; and accelerating the electrons and holes of said pairs with an electric field so as to generate radiation. In certain embodiments the dopant is Fe. Corresponding radiation detecting apparatus, spectroscopy systems, and antennas are described.

Abstract: A detector for electromagnetic radiation in the range 80 GHz to 4 THz comprises a laser light source (115) an optical modulator (13) arranged to modulate light from the laser light source (11) and a filter system (17) for selecting a defined range of frequencies of the modulated light. The optical modulator is an electroabsorption modulator (13) with an antenna (15) which is sensitive to electromagnetic radiation in the range 80 GHz to 4 THz. The signal received by the antenna (15) modulates the electric field across the electroabsorption modulator (13), whereby to modulate the light from the laser light source (11).

Abstract: An optoelectronic device has at least a first facet (S), a first waveguide (2) and a second waveguide (3). The waveguides are substantially coincident at the first facet (6), such that light travelling along the first waveguide (2) is reflected into the second waveguide (3) by the first facet (6). The first facet (6) is formed by precision cleaving. Preferably an etch feature is incorporated in the same mask level as that to define the waveguide core.

Abstract: A detector for electromagnetic radiation in the range 80 GHz to 4 THz comprises a laser light source (115) an optical modulator (13) arranged to modulate light from the laser light source (11) and a filter system (17) for selecting a defined range of frequencies of the modulated light. The optical modulator is an electroabsorption modulator (13) with an antenna (15) which is sensitive to electromagnetic radiation in the range 80 GHz to 4 THz. The signal received by the antenna (15) modulates the electric field across the electroabsorption modulator (13), whereby to modulate the light from the laser light source (11).

Abstract: An optoelectronic device has at least a first facet (S), a first waveguide (2) and a second waveguide (3). The waveguides are substantially coincident at the first facet (6), such that light travelling along the first waveguide (2) is reflected into the second waveguide (3) by the first facet (6). The first facet (6) is formed by precision cleaving. Preferably an etch feature is incorporated in the same mask level as that to define the waveguide core.

Abstract: A laser includes first and second feedback elements defining a laser cavity, and a gain medium within the laser cavity. The gain medium has first and second facets and an optical waveguide for guiding optical radiation between said first and second facets. The second feedback element is wavelength selective, and the optical waveguide is configured to direct optical radiation at an angle .theta. to the normal of the second facet.

Abstract: A semiconductor device, preferably a laser device such as a signal generator, a signal amplifier or a signal detector e.g. a distributed feedback laser, which is implemented in III/V semiconductors. Such devices often require a barrier layer to encourage current flow to pass through the localised p/n-interface and this invention provides the barrier layer in the form of a layer of hole trapping semiconductor material located between and in contact with two p-type layers. III/V semiconductors contain at least one of indium, gallium and aluminum and at least one of phosphorus and arsenic but the preferred devices are laser devices implemented in various types of indium phosphide except for the active zone wherein photons are generated. The active zone is preferably formed of ternary and/or quaternary semiconductors. In the preferred structures the barrier layer is formed of chromium doped indium phosphide which is located between two layers of p-type indium phosphide.