A device for converting electromagnetic radiation into electricity comprises an expander that includes a conical shape having an axis and a curved surface that is configured to reflect electromagnetic radiation away from the axis to expand a beam of the electromagnetic radiation; and one or more energy conversion components configured to receive a beam of electromagnetic radiation expanded by the expander, and to generate electricity from the expanded beam of electromagnetic radiation. With the expander's curved surface, a beam of electromagnetic radiation that is highly concentratedhas a large radiation fluxmay be converted into a beam that has a larger cross-sectional area. Moreover, one can configure, if desired, the curved surface to provide a substantially uniform distribution of radiation across the expanded cross-sectional area. With such an expanded beam the one or more energy conversion components can efficiently convert some of the electromagnetic radiation into electricity.

A device for optically imaging at least a part of an object, the device having an optical axis and including a two-dimensional first array of first microlenses, having a first side intended to face the object, and a second side, opposite the first side, a two-dimensional second array of second microlenses, each first microlens being aligned with a second microlens on an axis parallel to the optical axis, wherein each first microlens comprises a first catoptric system, and preferably a first catadioptric system.

A device for converting electromagnetic radiation (e.g., nonuniform laser light) into electricity comprises an expander that includes a conical shape having an axis and a curved surface that is configured to reflect electromagnetic radiation away from the axis to expand a beam of the electromagnetic radiation; and one or more energy conversion components configured to receive a beam of electromagnetic radiation expanded by the expander, and to generate electricity from the expanded beam of electromagnetic radiation. With the expander's curved surface, a beam of electromagnetic radiation that is highly concentratedhas a large radiation fluxmay be converted into a beam that has a larger cross-sectional area. Moreover, one can configure, if desired, the curved surface to provide a substantially uniform distribution of radiation across the expanded cross-sectional area. With such an expanded beam the one or more energy conversion components can efficiently convert the electromagnetic radiation into electricity.