Grating-assisted directional coupler filters using AlGaAs/GaAs MQW waveguides

Wavelength demultiplexing in the 800 nm region is demonstrated using grating-assisted vertical codirectional coupler filters formed in two AlGaAs/GaAs multiple quantum well (MQW) ridge waveguides. A filter bandwidth as narrow as 3 nm (full width at half maximum) and interwaveguide coupling efficiency of 95% with a coupling length of only 430 mu m were achieved. Channel spacing of 4 nm was obtained for five-channel wavelength demultiplexing with crosstalk suppression in excess of 10 dB.<
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