Demultiplexing systems and methods are discussed which may be small and accurate without moving parts. In some cases, demultiplexing embodiments may include optical filter cavities that include filter baffles and support baffles which may be configured to minimize stray light signal detection and crosstalk. Some of the demultiplexing assembly embodiments may also be configured to efficiently detect U.V. light signals and at least partially compensate for variations in detector responsivity as a function of light signal wavelength.