Patent ID: RE43889

Claim:
An infrared radiation photodetector comprising: a plurality of first elongate semiconductor elements for absorbing infrared radiation thereby creating electrical carriers, the plurality of first elongate elements being arranged to form a first one-dimensional diffraction grating for infrared radiation; a plurality of second elongate semiconductor elements for absorbing infrared radiation thereby creating electrical carriers, the plurality of second elongate elements being arranged to form a second one-dimensional diffraction grating for infrared radiation, the plurality of second elongate elements being substantially perpendicular to and intersecting the plurality of first elongate elements so as to form a two-dimensional diffraction grating having a first common major surface and a second common major surface, the second common major surface being opposite the first common major surface; at least a portion of at least one of the first and second elongate elements being enlarged so as to form a collector element, each collector element forming a portion of the first common major surface and a portion of the second common major surface; at least one semiconductor carrier collector for collecting electrical carriers thus created by the first and second elongate elements, each respective carrier collector being formed in a portion of a respective collector element so as to form a portion of one of the first common major surface and the second common major surface; a first electrical contact which is electrically connected to the at least one carrier collector; a second electrical contact which is electrically connected to at least one of the plurality of first elongate elements and the plurality of second elongate elements, the first contact and the second contact being disposed so as to provide for electrical carrier flow through the first and second elongate elements; and a reflector for infrared radiation, the reflector being closer to the second common major surface of the two-dimensional diffraction grating than to the first common major surface of the two-dimensional diffraction grating.