Low aberration concave grating for re-configurable optical add/drop multiplexer applications

We report an SOI based 1×4 coarse wavelength-division-multiplexer (CWDM) planar concave grating multiplexer/demultiplexer and its application in re-configurable optical add/drop multiplexer (ROADM) system. We employed recursion numerical method to build a low aberration, non-circle grating circle model of concave grating. We fabricated the device using CMOS compatible silicon planar integration technology. The concave grating multiplexer wavelengths are well fitted within ITU-T standard. We also fabricate a prototype of ROADM comprising two CWDMs and four wide-band optical switches. The ROADM function performance is presented.