A cylindrical illumination confocal spectroscopy system has a fluidic device having a fluid channel defined therein, an objective lens unit arranged proximate the fluidic device, an illumination system in optical communication with the objective lens unit to provide light to illuminate a sample through the objective lens unit, and a detection system in optical communication with the objective lens unit to receive at least a portion of light that passes through the objective lens unit from the sample. The illumination system includes a beam-shaping lens unit constructed and arranged to provide a substantially planar illumination beam that subtends across, and is longer than, a lateral dimension of the fluid channel.