Echelle grating – curved wave-guide demultiplexer for photonic integrated circuits

A grating spectrometer integrated with curved output wave guides was designed and fabricated in GaAs-AlGaAs waveguide structure for use in the 1 mum wavelength range. By incorporating curved wave guides, a larger separation between output facets was obtained. This is desirable for future integration. High-quality patterns were fabricated by focused ion beam lithography and reactive ion etching. Eight outputs with a channel spacing of 2 nm were obtained. The potential of the structure for integration with active components is discussed.