This disclosure defines an infrared image detector formed in a block of semiconductor material by etching slots in the semiconductor material. The slots define the individual detectors, effectively isolate them from each other both optically and electrically, and permit the detectors to be placed very close to each other. Biasing slots are etched in each detector and on two opposing sides of the detector and the walls of the slots are made highly conductive by an impurity diffusion or coating or alternatively the slots is filled with a conducting material. The conducting layer or material in each slot is connected to a conductor on the surface of the semiconductor wafer so that the conductor inside the biasing slot serves as an electrical contact for the detector. The detectors are biased electrically by applying a voltage difference between two different sets of conducting slots.

An ionizing radiation detector comprises a flat substrate having a plurality of etched parallel ridges on one surface. The parallel sides of the ridges carry a thin layer of a conducting material, acting as an electrode. A particle or radiation beam to be detected impinges on the ridges, in a direction normal to the plane of the substrate, so causing electron/hole carriers production within the ridges. The carriers migrate to the electrodes, in a direction perpendicular to the beam, thereby inducing charge on the electrodes. The readout can be extremely rapid, since the carriers need to migrate only a very small distance to the side of the ridge.

Phase enhancement by resonant Fabry-Perot picture elements in III-V semiconductor spatial light modulators (SLMs) is disclosed. For 95% reflecting electrodes, a phase modulation of 0.7.pi. rad is found in transmission when the electrooptic input phase is 0.06.pi. rad. A resonant phase-dominant SLM in a 1.7-.mu.m-thick AlGaAs/GaAs multiple quantum well (MQW) structure can employ field effects and carrier-induced electrooptic effects within the MQWs.

A detector for ionizing radiation, comprising a semiconductor plate having electrode strips, which extend along the upper surface of the plate, which is passed through by the rays, from an edge portion of the semiconductor plate in the direction of its opposite edge portion, and which communicate with a signal utilizing arrangement, the latter of which forms signals from the signals tapped from the electrode strips in correspondence with or indicative of the locations of the focal points of the radiation spots produced on the detector. All electrode strips are positioned on one side of the semiconductor plate, and vary in cross-section along the direction of their longitudinal extension pursuant to a predetermined function, and wherein on the other side of the semiconductor plate there is mounted a common electrode covering substantially the entire surface of the plate.

An improved semiconductor gamma camera is disclosed. The gamma camera includes a p-i-n semiconductor diode which detects the presence and energy of gamma radiation from a source. Typically the source is radioactive material in a patient organ which is detected and then interpreted by a doctor while diagnosing the condition of that organ. The detector includes an improved electrical connection technique to allow the p-i-n diode to be connected to electronic circuitry necessary to provide spatial and energy information. In the improved camera first a passivation layer is deposited on both faces of the p-i-n diode and then a resistive layer is applied to form a reliable easily reproduced electrical contact to the junction. These two layers in combination prevent foreign matter from contacting the semiconductor material comprising the detector while providing interconnection to the electronic circuitry.