Abstract: A Laser Power Converter (LPC) device (1) comprises an anti-reflection coating (10), a window layer (20), an active region (30), an electron blocking layer (40), a Distributed Bragg Reflector (DBR) (50) and a substrate (60). The device further comprises an anode (70), a cathode (80) and insulating layers (90). The active region (30) is formed of indium gallium arsenide phosphide (InGaAsP), with the proportion of chemical elements in the InGaAsP layers being InyGa1-yAsxP1-x, and is designed to convert electromagnetic radiation having a wavelength of 1.55 ?m into electrical energy. However, the exact composition of the InGaAsP is chosen to have a band-gap wavelength at slightly above 1.55 ?m because in operation the device heats up and the band-gap shifts to longer wavelengths. To obtain a suitable band-gap the composition may be InyGa1-yAsxP1-x, where x=0.948, 0.957, 0.965, 0.968, 0.972 or 0.976 and y=0.557, 0.553, 0.549, 0.547, 0.545 or 0.544 respectively.

Abstract: A light emitting semiconductor device (401) has an active region (405) formed of Bismuth (Bi) and one or more other group V elements. In a particular embodiment the III-V material comprises Gallium Arsenide (GaAs) in addition to Bismuth. The inclusion of Bismuth in the III-V material raises the spin-orbit splitting energy of the material while reducing the band gap. When the spin-orbit splitting energy exceeds the band gap, Auger recombination processes are inhibited, reducing the sensitivity of the light emitting semiconductor device (401) to changes in ambient temperature.

Abstract: A Laser Power Converter (LPC) device (1) comprises an anti-reflection coating (10), a window layer (20), an active region (30), an electron blocking layer (40), a Distributed Bragg Reflector (DBR) (50) and a substrate (60). The device further comprises an anode (70), a cathode (80) and insulating layers (90). The active region (30) is formed of indium gallium arsenide phosphide (InGaAsP), with the proportion of chemical elements in the InGaAsP layers being InyGa1-yAsxP1-x, and is designed to convert electromagnetic radiation having a wavelength of 1.55 ?m into electrical energy. However, the exact composition of the InGaAsP is chosen to have a band-gap wavelength at slightly above 1.55 ?m because in operation the device heats up and the band-gap shifts to longer wavelengths. To obtain a suitable band-gap the composition may be InyGa1-yAsxP1-x, where x=0.948, 0.957, 0.965, 0.968, 0.972 or 0.976 and y=0.557, 0.553, 0.549, 0.547, 0.545 or 0.544 respectively.

Abstract: A light emitting semiconductor device (401) has an active region (405) formed of Bismuth (Bi) and one or more other group V elements. In a particular embodiment the III-V material comprises Gallium Arsenide (GaAs) in addition to Bismuth. The inclusion of Bismuth in the III-V material raises the spin-orbit splitting energy of the material while reducing the band gap. When the spin-orbit splitting energy exceeds the band gap, Auger recombination processes are inhibited, reducing the sensitivity of the light emitting semiconductor device (401) to changes in ambient temperature.

Abstract: A spectrophotometer comprising a monolithic semiconductor substrate, one or more wavelength dispersing means, and one or more wavelength detecting means, wherein the monolithic substrate (1) has waveguide means (2) and one or more resonators (3-14) acting as detectors of particular light wavelengths and disposed in proximity to the waveguide means in such a way that evanescent light coupling can occur for said light wavelengths.