M3E.2.pdf OFC 2014 © OSA 2014 Fast Dynamic Wavelength and Path Scheduling in a Monolithic 8×8 Switch Q. Cheng 1 , R. Stabile 2 , A. Rohit 2 , A. Wonfor 1 , R. V. Penty 1 , I. H. White 1 and K.A. Williams 2 1 Centre for Photonic Systems, Electrical Division, Department of Engineering, University of Cambridge, United Kingdom 2 COBRA Research Institute, Eindhoven University of Technology, Eindhoven, The Netherlands Author e-mail address: qc223@cam.ac.uk Abstract: The control plane is implemented for the first time to allow scheduling and power leveling in a monolithic 8×8 space and wavelength selective cross-connect. 16 dynamic data connections are established within 16μs. OCIS codes: 130.6622 Subsystem integration and techniques, 130.4815 Optical switching devices 1. Introduction The relentless scaling in required network bandwidth combined with the highly bursty nature of traffic in computer networks and data centers is leading to renewed interest into high-bandwidth, packet-compliant, optically-switched interconnects. So far the connectivity required for optical switches in such applications has far outstripped the capability of demonstrated packet-compliant photonic systems. However, the combination of wavelength domain wavelength selective switching and space domain photonic switching offers a powerful route to much higher connectivity [1]. The OSMOSIS architecture demonstrated 64 way connectivity using eight WDM input connections, and a multi-stage implementation is projected to scale to a thousand ports [2]. The use of discrete photonic components in such demonstrators has however been prohibitive in the numbers of fiber connections, component numbers and overhead in terms of assembly, calibration, synchronization, management and energy use. The recent integration of an eight port wavelength and space selective switch allows for much of this complexity to be contained within one single 14mm × 6mm chip [3, 4]. Extensive photonic integration means that all switch states may be synchronized, allowing considerable reductions in control complexity, calibration, and an improved control of optical losses. In this work, we now implement a control plane for the first time to demonstrate simultaneous dynamic routing in both wavelength and space domain on a monolithically integrated photonic chip. Sixteen unique data connections are implemented within a time period of 16 μs by uploading the Round Robin schedule to the FPGA switch controller. Automated routing is demonstrated for four wavelengths from each of four inputs to one output and automated measurements are performed verify connectivity. Fig. 1 Photograph of the 8×8 wavelength and space switch. 2. Device details A photograph of the 8×8 cross-connect is shown in Fig. 1. The switching circuit is a synchronous broadcast-and- select photonic space switch with wavelength granularity routing. This is implemented with semiconductor optical amplifier gates. Up to eight independent wavelengths may be carried on each of eight fibers to achieve sixty-four- way distribution. The shuffle network is fully integrated to minimize the numbers of optical fiber connections and radically reduce time-of-flight delays. Wavelength domain switching is implemented with a second stage of wavelength selective switches based on a cyclic router, SOA gates and a broadband fan-in. The architecture and routing map is detailed for the case of an earlier and smaller 4×4 prototype [1]. Any input wavelength from any