Fabrication of unequal channel spacing arrayed-waveguide grating multiplexer modules

16-channel arrayed-waveguide grating multiplexer modules with unequal channel spacing have been fabricated using SiO/sub 2//Si waveguides. The authors obtained a crosstalk of <-25 dB to neighbouring and all other channels. The fibre-to-fibre losses for 16 ports range from 2.8 to 3.1 dB and the polarisation dependencies are <0.007 dB.