1. An optical and detection system for a flow cytometer having a flow channel with an interrogation zone and an illumination source that impinges the interrogation zone from a particular direction, the optical system comprising: a lens subsystem including: a collimating element comprising an achromatic doublet lens, wherein the collimating element receives and collimates light from the interrogation zone; an aplanatic meniscus lens optically paired with the achromatic doublet lens, wherein the combination of the achromatic doublet lens and the aplanatic meniscus lens has an effective focal length of approximately 20 millimeters; a light dispersion element that disperses the collimated light into a continuous wavelength spectrum of light; a focusing lens that focuses the spectrum of light onto an array of adjacent detection points; and a plurality of contiguous detectors that detect light at the adjacent detection points.