The present invention generally provides an optical wavelength router that includes at least one dendritic taper region. The dendritic taper region includes at least one dendritic taper which has a trunk and at least one branch optically coupled to the trunk. In addition to the dendritic taper region, the optical wavelength router includes at least one input waveguide, a input slab waveguide, an arrayed waveguide grating, an output slab waveguide, and at least one output waveguide. The improved optical wavelength router provides a wide passband width without a substantial effect on insertion loss.