$N \times N$ Cyclic-Frequency Router With Improved Performance Based on Arrayed-Waveguide Grating

We have developed an NxN cyclic-frequency router with improved performance by employing two types of modified configuration; a uniform-loss and cyclic-frequency (ULCF) arrayed-waveguide grating (AWG) and an interconnected multiple AWG. We have demonstrated a compact 50-GHz-spacing 64x64 ULCF-AWG router with low and uniform insertion losses of 5.4-6.8 dB and frequency deviations from the grid of less than plusmn8 GHz. We have also demonstrated a 100-GHz-spacing 8x8 interconnected multiple-AWG router with a practical configuration, very low and uniform insertion losses of 2.3-3.4 dB, and frequency deviations from the grid of less than plusmn6 GHz. We discuss the suitable or realizable scale N of the two types of routers by comparison with a conventional AWG router in terms of optical and dimensional performance and productivity.