Multi-band arrayed waveguide grating with improved insertion loss and wavelength accuracy

Abstract

A planar lightwave circuit generalized for handling any given band of multiple bands of a wavelength range, including a first grating element handling a first group of bands; and a second grating element handling a second group of bands. The first and second groups of bands overlap in the wavelength range, and may be spaced apart by a fixed wavelength value. By providing two periodic grating elements handling alternating bands, their free spectral range is allowed to expand, improving their roll-off characteristics. By providing separate inputs for each band, wavelength accuracy can be improved. Device flexibility can be further improved by using switch and interleaver fabrics at the inputs and outputs. The resultant device, generalized to handle any given band within a wavelength range, eliminates the need for separate component design and inventory tracking otherwise necessary.