Silicon-on-Insulator-Based Compact Optical Demultiplexer Employing Etched Diffraction Grating

A compact optical demultiplexer with etched diffraction grating (EDG) is designed and fabricated on a silicon-on-insulator (SOI) material. Several 90°turning mirrors are used to bend the waveguides, and the size of the EDG-based demultiplexer is minimized to only 16 x 1.7mm². The crosstalk is about 18 dB. The on-chip loss is about 18.2 dB, which is composed of about 16.9 dB excess loss and 1.3 dB diffraction loss. Measures to improve the performance are discussed.