Photodetector focal plane arrays with enhanced detection capability

A method for concentrating IR radiation in a dielectric structure, said method comprising:

• 1) providing a photodetector focal plane array (FPA) comprising:
• a) photodetectors that are photosensitive in the IR region of the electromagnetic spectrum;
• b) light-concentrating dielectric structures in a form of arrays comprising elements with three-dimensional geometrical shapes, wherein the elements have a first surface, a second surface, and tapered sidewalls that taper inwardly to a portion of said second surface that has a reduced width, wherein a photodetector is joined to the portion that has a reduced width;
• and
• c) a metallic layer that is disposed over the tapered sidewalls of the elements and the portion of the surface of the elements that has a reduced width, wherein the metallic layer provides mirror reflection properties to concentrate electromagnetic fields towards the detectors;
• and
• 2) directing radiation into the interior of the tapered structure wherein at least some of the radiation reflects off at least one of the surfaces of the tapered side walls toward another surface of the tapered side walls.