Large Port Count Wavelength Routing Optical Switch Consisting of Cascaded Small-Size Cyclic Arrayed Waveguide Gratings

We propose a highly scalable switch architecture suitable for client-side cross-connect switches in reconfigurable optical add/drop multiplexers and optical switching in data centers. It consists of cascaded cyclic arrayed waveguide gratings (AWGs). We develop a 270 × 270 prototype switch consisting of an assembly of arrayed small switches and couplers and AWGs that are fabricated on planar lightwave circuit chips. Transmission experiments verify its technical feasibility.

I. Introduction

Optical switching systems offer several advantages over electrical equivalents such as modulation format transparency, large capacity, and low power consumption. In backbone and metro networks, wavelength path routing using reconfigurable optical add/drop multiplexers (ROADMs) has been widely introduced, although current ROADMs do not offer colorless, directionless, and contentionless (C/D/C) functions. They are desired for the next generation ROADMs and to this end various architectures that utilize large optical space switches have been proposed [1]–[3]. The required switch scale tends to be very large and hence it can be costly when the number of add/drop wavelengths and node degree become large. Compact and cost-effective optical switches with modular growth capability are essential.