Wavelength selective switch using arrayed waveguides with linearly varying refractive index distribution

A wavelength selective switch and demultiplexer using arrayed waveguides with linearly varying refractive index distribution is proposed. The thickness of the arrayed waveguides is varied linearly using selective metal-organic vapor phase epitaxy (MOVPE) growth. The dependence on growth conditions and mask pattern of the structural and optical characteristics of the arrayed waveguides are determined. Successful wavelength demultiplexing on four output ports with a wavelength separation of approximately 25 nm is realized using input and output star couplers based on Rowland circle geometry. Finally, wavelength selective switching by dynamic refractive index control of the arrayed waveguides is described.