title: Improvement of the power spectral response in the three-guided coupler demultiplexer.
abstract: To improve the power spectral response of directional coupler type demultiplexers, the three-guide coupler with varying coupling coefficients along the light propagation direction is theoretically examined. A new configuration of the three-guide coupler is presented, which gives 0.16- and 0.13-microm rejection bandwidths of -20 dB in the 1.3- and 1.55-microm wavelength regions, respectively. These are 5 times wider than the conventional two-guide coupler demultiplexer. Furthermore, a simple design method for obtaining the coupler parameters is presented.
authors.forename: K
authors.initials: K
authors.lastname: Kishioka