A system for detecting a plurality of analytes in a sample includes an aperture array and a lens array for generating and focusing a plurality of excitation sub-beams on different sub-regions of a substrate. These sub-regions can be provided with different binding sites for binding different analytes in the sample. By detecting the different luminescent responses in a detector, the presence or amount of different analytes can be determined simultaneously. Alternatively or in addition, collection of the luminescence radiation can be performed using the lens array for directly collecting the luminescence response and for guiding the collected luminescence response to corresponding apertures. The excitation sub-beams may be focused at the side of the substrate opposite of the lens array, and an immersion fluid is provided between the lens array and the substrate to increase the collection efficiency of the luminescence radiation.