Abstract:
Semiconductor hybrid components, especially linear infrared detectors produced by hybridization. A main substrate has integrated thereon active elements which cannot be produced on a silicon substrate. The substrate is made, for example, of AsGa, InP, HgCdTe or PbTe. Several silicon chips are mounted on the main substrate, by hybridization using indium balls. These chips include the read and multiplexing circuits. The silicon chips remain of limited size (a few millimeters) so that the differential thermal expansion stresses are limited, but the detection array may be produced as one piece without butt-joining. It is therefore possible to produce arrays of great length (several centimeters) and of high resolution (at least a thousand points).
Abstract:
Disclosed is an integrated direction finder that can be used to determine the direction of a light beam and, in particular, a laser beam. This direction finder has a substrate transparent to the light beam and means on the rear face to channel a part of the light flux received on this face to the front face which has several photodetector elements. Application to optical measurements.
Abstract:
A photodetector arrangement capable of detecting high-power-light flux and including a set of elementary photodetectors each one of which is individually tested to determine that it has no defects. Each of the photodetectors which is found to be free of objectionable defects is connected in parallel to a common conducting line to thus produce a combined output when radiation impinges on the detector surface. The connection can be hard wired or provided through a set of transistors acting as connection control intermediaries between the good photodetectors and the common conducting line. The active areas of only good photodetectors are thus combined to form a large photodetector area of any desired shape or size without the usual reliability problems. The selective control of the transistors can further be provided by auxiliary control photodetectors to additionally automatically control the size of the active area in response to the area of light being detected or a control light beam.
Abstract:
Quantum well detector, in which the active detection zone (2) occupies only a limited area of the device and in which a diffraction grid (5) having a larger surface area than this zone thereby makes it possible to couple to it a greater light flow than that corresponding to the surface area of this zone. In this way, the sensitivity of the device is increased. Application: Detection of optical radiation.
Abstract:
Device for the detection and processing of optical radiations, comprising at least one quantum well having asymmetric composition, said well consisting of a stack of layers of materials having differing gaps.
Abstract:
An electronic bolometer comprises at least a quantum well between two barrier layers. It has an input side parallel to the quantum-well layer and receiving a beam at a quasi-normal incidence angle. Two electrodes disposed perpendicularly to the quantum-well layers allow to measure a change in the resistivity of said quantum well.
Abstract:
An electromagnetic wave detector formed of semiconductor materials includes at least one quantum well in which there is provided a fine layer of a material with a gap width that is smaller than that of the quantum well layer. For example, in the case of a GaAlAs/GaAs/GaAlAs, there is provision for a fine layer of InAs. In this way, the difference of energy levels between the two permitted levels is increased and detection of short wavelengths may be accomplished.
Abstract:
An electromagnetic wave detector comprises a stack of quantum wells included between an ohmic contact and a rectifier junction which may be a barrier (Al.sub.y Ga.sub.1-y As) with a forbidden band width that is greater than that of the barriers of the quantum wells.
Abstract:
A bi-functional optical detector including a first active photoconduction detection element configured to detect light within first and second wavelength ranges, a first diffraction grating associated with the first detection element and configured to couple the light within the first wavelength range so that the first active photoconducting detection element detects the light in the first wavelength range, a second active photoconduction detection element configured to detect light within the first and second wavelength ranges, and a second diffraction grating associated with the second detection element and configured to couple the light within the second wavelength range so that the second active photoconduction detection element detects the light in the second wavelength range. Also included is a third active photoconduction detection element associated with the first detection element and configured to detect the light within the first and second wavelength ranges, a fourth active photoconduction detection element associated with the second detection element and configured to detect the light within the first and second wavelength ranges, and a common contact layer separating the first and second detection elements from the third and fourth detection elements.
Abstract:
The disclosure relates to a bispectral electromagnetic wave detector including at least one first and one second overlaid plane active detector elements separated by a common layer, said first and second detector elements being sensitive to the different wavelengths; a first means of connection connected in common to said first and second detector elements, a second means of connection connected to said first detector element, and a third means of connection connected to said second detector element; means for applying successively a control voltage to each means of connection; and means connected to said first means of connection to detect a photoconduction current each time a control voltage is applied. The invention is used in applications requiring detection of electromagnetic waves in two bands of different wavelengths.