A spectrometer comprising an imaging assembly comprising: a substrate; a first and a second module (120a', 120b') disposed on said substrate, containing associated first and second arrays (100a', 100b') of detector elements and positioned on the substrate such that the first and second arrays have an elongation along a first axis and are spaced from one another on the first axis so as to form a gap between the first and second arrays; a gap filler module disposed on said substrate, and including a gap filler array of detector elements spaced from said first axis, the gap filler array being at least as long as the gap and smaller than the elongation of either of the first or second arrays; a first slit and a second slit disposed on said substrate and having an elongation along a second axis spaced from and generally parallel to the first axis, each of the first and second slits being at least as long as the first and second arrays (100a', 100b') respectively; and a gap filler slit that is at least as long as the gap, disposed on said substrate spaced from said first axis, said second axis, and said gap filler array, such that the gap, the gap filler slit, and the gap filler array are generally positioned along a third axis that is generally perpendicular to the first axis and the second axis and the combination of slits (110a', 110b', 110c') and arrays (100a', 100b', 100c') of detector elements generally form the shape of a plus sign; and a dispersive element, wherein beams of electromagnetic radiation incident through the first slit and the second slit are dispersed by the dispersive element, such that resultant spectra of the electromagnetic radiation is projected onto the first array and/or the second array, and wherein beams of electromagnetic radiation incident through the gap filler slit are dispersed by the dispersive element, such that the resultant spectra of the electromagnetic radiation is projected onto the gap filler array. a substrate; a first and a second module (120a', 120b') disposed on said substrate, containing associated first and second arrays (100a', 100b') of detector elements and positioned on the substrate such that the first and second arrays have an elongation along a first axis and are spaced from one another on the first axis so as to form a gap between the first and second arrays; a gap filler module disposed on said substrate, and including a gap filler array of detector elements spaced from said first axis, the gap filler array being at least as long as the gap and smaller than the elongation of either of the first or second arrays; a first slit and a second slit disposed on said substrate and having an elongation along a second axis spaced from and generally parallel to the first axis, each of the first and second slits being at least as long as the first and second arrays (100a', 100b') respectively; and a gap filler slit that is at least as long as the gap, disposed on said substrate spaced from said first axis, said second axis, and said gap filler array, such that the gap, the gap filler slit, and the gap filler array are generally positioned along a third axis that is generally perpendicular to the first axis and the second axis and the combination of slits (110a', 110b', 110c') and arrays (100a', 100b', 100c') of detector elements generally form the shape of a plus sign; and