# Evolution of System Embedded Optical Interconnect in Sub-Top-of-Rack Data Center Systems
## 6 Aurora--Hyperscale Integrated Optical and Photonics Ecosystem Demonstrator Platform  
The FP7 PhoxTroT, H2020 Nephele and H2020 COSMICC projects developed a test and measurement platform, named \"Aurora\", that enabled the systematic characterization of optical transceivers, board-to-board optical connectors and both embedded and passive optical circuit boards, as shown in Figure 14[21; 22].  
Figure 14: Images taken of EU H2020 “Aurora” hyperscale integrated photonic ecosystem demonstrator during its exhibition at ECOC 2019 in Dublin: (**a**) complete data center rack compliant Aurora platform; (**b**) test daughtercard, which includes two microphotonic test mezzanine cards hosting different PICs; (**c**) silicon PIC with attached vertical grating coupler and fiber array unit; (**d**) silicon PIC with integrated adiabatic coupler and polymer waveguide ribbon; (**e**) microphotonic test mezzanine card; (**f**) glass waveguide backplane provided by Fraunhofer IZM [23].  
The cross-project \"Aurora\" platform is designed to hold different types of advanced optical interconnect technologies including embedded and discrete polymer and glass waveguide circuits, optical PCB connectors and transceiver and switch technologies including advanced silicon photonics devices.  
Aurora comprised a test enclosure with interlocking and interchangeable mezzanine electro-optical test boards, electro-optical daughterboards and electro-optical backplanes. This allows the characterization of different optical components with different technical maturity levels either alone or in combination with other technologies. The initial work was carried out during the PhoxTroT project (which concluded in May 2017) [24]. The H2020 Nephele [25] and H2020 COSMICC [26] projects further developed the Aurora universal test platform, building it into an open-source test board design portfolio, which was widely disseminated. Organizations or consortia can use Aurora to test diverse integrated optical and photonic interconnect technologies on a common platform. Researchers only need to focus on the design of small simple test cards using the common design form factors, thus giving significant time and cost savings. The need to design a new evaluation platform from scratch is avoided, allowing researchers to make more technology iterations and accelerate the movement of the target technology through the TRL levels. The test boards can be used on their own or connected to appropriate communication platforms.  
An international standard (IEC 62150-6 Ed1--Basic Test and Measurements, Universal Test Cards for Test and Measurement of Micro Board Photonic Devices) will be published in 2022. This standard defines the generic electro-optic mezzanine board for the test and measurement of micro-optical and microphotonic devices, including a wide diversity of photonic integrated circuit (PIC) technologies spanning technologies from transceivers, switches, sensors, neuromorphic networks and LiDAR to quantum integrated circuits. In addition to European research and development projects FP7 PhoxTroT [27], H2020 Nephele [28] and H2020 COSMICC [6], the Aurora platform with new variants of these mezzanine boards has formed the basis of the United States of America High Density User Packaging Group (HDPuG) Opto-electronics project, which culminated in a comprehensive round-robin between multinational organizations including Cisco, Corning, Nokia, Seagate, Fujitsu, Huber + Suhner, Fraunhofer IZM, R&M, Samtec and TTM Technologies.