ARRAY WAVEGUIDE DIFFRACTION GRATING

摘要

An array waveguide diffraction grating causing reduced crosstalk. An optical waveguide section (10) comprising a core and a clad is formed on a silicon substrate (11), and the core forms a following waveguide arrangement. A first slab waveguide (13) is connected to the output sides of a plurality of optical input waveguides (12), and a plurality of array waveguides (14) of different length are arranged side by side on the output sides and connected. A second slab waveguide (15) is connected to the output sides of the array waveguides (14), and a plurality of optical output waveguides (16) are connected to the output sides thereof. A plurality of multiplexed lights having different wavelengths entering the optical input waveguides (12) are demultiplexed and outputted. The core is formed by flame hydrolysis deposition. The number of deposition layers is 13 or above. The standard deviation in the phase difference distribution of the array waveguides (14) is reduced to 0.6 rad or below and the crosstalk is reduced to 40 dB or below by setting the standard deviation of the fluctuation of the refractive index of the core constituting the plurality of array waveguides to 4.84X10<-6> or below.