An optical interrogation system and a method are described herein that enable the interrogation of one or more biosensors which can be located within the wells of a microplate. In one embodiment, the optical interrogation system has a tunable laser, N-fiber launches, N-lenses and N-detectors that are set-up to interrogate N-biosensors. In another embodiment, the optical interrogation system has a tunable laser, N-fiber launches, N+1 lenses and N-detectors that are set-up to interrogate N-biosensors.