Phase matched optical grating

摘要: The invention relates to phase matched optical gratings for performing signal multiplexing and demultiplexing in communications networks. In prior art there is a linearity error between the grating line outputs on focal line, comparing center output surrounding outputs. This corresponds relative difference each which limits passband. case of AWG this degradation comes primarily from field aberrations star coupler. present has found that if disposed ellipse instead circular arc, while defines substantially an optimum can be where eliminated, all have same phase. As result, creates uniform passbands across WDM spectrum.