  Three-dimensional spatiotemporal tracking of microscopic particles in
multiple colors is a challenging optical imaging task. Existing approaches
require a trade-off between photon-efficiency, field of view, mechanical
complexity, spectral specificity and speed. Here, we introduce multiplexed
point-spread function engineering that achieves photon efficient, 3D,
multicolor particle tracking over a large field of view. This is accomplished
by first chromatically splitting the emission path of a microscope to different
channels, engineering the point-spread function of each, and then recombining
them onto the same region of the camera. We demonstrate our technique for
simultaneously tracking five types of emitters in-vitro, as well as
co-localization of DNA loci in live yeast cells.
