Echelle grating WDM (de-)multiplexers in SOI technology, based on a design with two stigmatic points

We present ultra-compact integrated optical echelle grating WDM (de-)multiplexers for on-chip optical networks. These devices are based on a design with two stigmatic points. The devices were fabricated using Silicon-On-Insulator (SOI) photonic waveguide technology thus the smallest version of the (de-)multiplexer occupies an area of only 250x200 μm. We will show measurement results on different variations of the echelle grating devices. In the measurements, we found a channel to channel isolation of 19 dB. The minimum insertion loss, relative to a straight waveguide, is only 3 dB with a channel to channel variation of 0.5 dB.