Abstract: The present invention comprises apparatuses and methods, for routing optical communication signals over all DWDM wavelength channels. Incoming wavelength channels are separated into a plurality of sub-groups having a smaller optical bandwidth. Wavelength channels within each sub-group are then acted upon independently by a filter, or switch, tunable and operable over the bandwidth of each sub-group. The invention may be embodied in a plurality of dynamic wavelength routing circuits including 1×N and N×N circuits. The 1×N circuit embodiments may be used when the filter free-spectral range is smaller than the full DWDM bandwidth. These embodiments are less complicated than the N×N circuit embodiments, but do not provide the same routing bandwidth. The N×N circuit embodiments may be used to route the full DWDM bandwidth and may be used for other routing operations having large bandwidth demand.