Wavelength routing device having wide and flat passbands

Abstract

A wavelength routing device 500 includes a pair of dielectric slabs 10, 20 that are interconnected by an optical grating 30. The first dielectric slab 10 includes input ports for receiving optical signals that are routed to output ports of the second dielectric slab 20 according to their wavelengths. Y-branch splitters 70-1 are connected to the first dielectric slab. Splitters 70-1 each include a pair of adjacent waveguides, having widths (w.sub.1), that are separated from each other by a center-to-center distance (c.sub.1). Y-branch splitter 70-2 is connected to the second dielectric slab. Splitter 70-2 includes a pair of adjacent waveguides, having widths (w.sub.2), that are separated from each other by a center-to-center distance (c.sub.2). Preferably, 4w.sub.2 >w.sub.1 >1.5w.sub.2, and 4c.sub.2 >c.sub.1 >1.5c.sub.2. Associated with this routing device is a figure-of-merit (B.sub.1 /B.sub.2) that exceeds 0.5, which represents a substantial improvement over prior art designs. Such devices 500 are particularly useful in applications where they need to be cascaded.

Dependencies are inferred from the claim text.