Project Objectives

Objective 1:
Develop InP-EML arrays, GaAs-VCSEL arrays, and InP-PD arrays, as the key optical components for low-cost and energy-efficient transceivers supporting an aggregate data rate of 200 Gb/s

SPRINTER will develop 4-fold InP EML arrays as the key building blocks of 4 lane transceivers for transmission distances up to 2 km, operating in O-band and supporting 50 Gb/s data rate per lane with OOK-NRZ modulation scheme. The EMLs will feature high-bandwidth (>35 GHz), low driving requirements (<1.5 Vpp) and high-output power (>5 dBm), supporting uncooled operation. Moreover, SPRINTER will reduce their fabrication cost and footprint by 50%, by carefully engineering the contact scheme of the modulator section. In parallel, SPRINTER will develop 4-fold SM GaAs VCSEL arrays as the key building blocks of 4 lane transceivers for transmission distances up to 500 m, operating at 1060 nm. The VCSELs will exhibit bandwidths above 30 GHz to support operation 50 Gb/s data rate per lane with OOK-NRZ. Regarding the receiving part, SPRINTER will develop two types of 4-fold InP-PD arrays. The first type will operate in the O-band, exhibiting high bandwidth (>35 GHz) and responsivity (>0.7 A/W) while the second will be optimized to operate at 1060 nm, exhibiting also high 3-dB bandwidth (>30 GHz) and responsivity (>0.65 A/W).

Objective 2:
Develop an ultra-fast tunable InP/Si3N4 external cavity laser, a LNOI-MZM and an InP-MZM as the key optical components for ultra-dynamic optical transceivers supporting data rate of 10 Gb/s

SPRINTER will develop a high-performance ECL source that will provide wide tunability in the S-band (1460 nm-1530 nm) and C-band (1530 nm-1565 nm), and ultra-high output optical power (100 mW). The ECL source comprises an InP reflective semiconductor optical amplifier (RSOA) as gain medium and a TriPleX waveguide circuit as external cavity in the form of two coupled micro-ring resonators (MRRs). The ECL will feature high side-mode suppression ratio (SMSR) (>60 dB), ultra-low linewidth (<300 Hz), negligible wavelength drift (<100 MHz), and high reproducibility accuracy (<50 MHz). The actuation of the cavity will be based on stress-optic phase shifters, formed by depositing lead zirconate titanite (PZT) electrodes on the TriPleX waveguides. SPRINTER will invest on the PZT technology, aiming to increase their bandwidth and thus the wavelength tuning speed of the ECL (>10 MHz), reduce the driving voltage required to achieve 2π phase shift (< 40V), and decrease their power consumption (<10 μW). The ECL will be hybridly integrated with a high-performance LNOI-MZM, to form a 10 Gb/s optical transmitter. The LNOI-MZM will feature ultra-low optical loss (<1 dB), extremely low Vπ (<0.9 V), high electro-optic bandwidth (> 30 GHz), and will be able to handle very high input optical power (>100 mW). In parallel, SPRINTER will also provide an equivalent 10 Gb/s optical transceiver replacing the LNOI-MZM with the mature InP-MZM technology of FhG. The InP-MZM will feature low optical loss (<3 dB), low Vπ (<1.5 V), and high electro-optic bandwidth (>20 GHz).

Objective 3:
Develop a hybrid photonic platform supporting ultra-low latency FSO and mmWave communication links toward a remote node, acting as a virtual fiber extender of a fixed fiber-optic network

SPRINTER will develop a novel hybrid, co-packaged FSO/mmWave transceiver supporting low latency, PtP connectivity between a node connected to an all-optical switching network, and a remote node, with data rates up to 10 Gb/s and distances up to 500 m. The FSO system will act as a virtual extender of the optical network, providing a zero-latency link while the mmWave system will operate in the E-band (73 GHz) and will act as a complementary communication system, improving the link reliability. The key building blocks of the node are based on the mature hybrid PolyBoard/TriPleX/InP photonic platform that i) enables the interoperability of the nodes with the optical network, ii) controls the operating mode (FSO or mmWave), and iii) provides the necessary optical components for the generation, modulation, amplification functionalities for both systems, and the fast beam steering and transmission of the mmWave signals by an integrated 4×4 planar antenna array. The transmission and reception of the FSO signals will be further assisted by external free-space optics for beam collimation purposes, while the reception of the mmWave signals will be facilitated by horn antennas. SPRINTER will also provide the necessary methods and tools for the alignment and tracking procedures for the FSO system.

Objective 4:
Develop 3D PolyBoard motherboard to host a novel ROADM for SDM networks

SPRINTER will take advantage of PolyBoard’s advanced toolbox and potential for fabrication in the third dimension to develop an active reconfigurable optical add-drop multiplexer (ROADM) with low reconfiguration time (<10 ms) for SDM networks, operating in O-band. The circuit will consist of two 3D PolyBoard multicore fiber (MCF) interposers and a 32×32 3D PolyBoard active optical switch based on the Benes non-blocking and fully reconfigurable architecture. The MCF interposers will provide low-loss interfaces (<1 dB) toward 8-core MCFs while the 32×32 active switch will consist of 144 crossbar switches, implemented as low-loss (<0.25 dB) 2×2 Mach-Zehnder interferometers (MZIs) with multi-mode interferometers (MMIs) as 3-dB couplers, laid across two polymer waveguide layers. The switching state of the MMI-MZIs will be controlled by thermal phase shifters in each of the MMI-MZIs’ arms. The transition between the waveguide layers will be enabled by low-loss (<0.25 dB) vertical 1×1 MMI structures. The remaining ports of the switch will be connected to single mode fibers (SMFs) to support add/drop functionalities. The SDM-ROADM will feature low crosstalk between ports (<30 dB), requiring low switching power (<10 mW). An already developed process for 3D routing of electrical lines through the polymer stack using both horizontal and vertical paths will be applied to allow for electrical connection to the phase shifters.

Objective 5:
Develop energy-efficient SiGe BiCMOS circuits and control units for SPRINTER prototypes

SPRINTER will rely on BiCMOS SiGe circuits to develop high-bandwidth transmitter and receiver electronics for 50 Gb/s with OOK-NRZ modulation scheme. A co-design methodology will be developed, targeting optimization of the interfaces of all electronics and optoelectronic components, minimizing the losses and maximizing the energy efficiency. SPRINTER will deliver 4-fold arrays of high-bandwidth (>35 GHz) drivers, firstly for the EMLs, featuring high output driving voltage swing (up to 2 Vpp) and low power consumption (0.8 W), as well as for the VCSELs, with high output modulation current swing (up to 10 mApp) and ultra-low power consumption (0.2 W). For the receiving part, SPRINTER will deliver 4-fold transimpedance amplifier (TIA) arrays, featuring high-bandwidth (>30 GHz), high gain (>65 dBΩ) and low power consumption (<0.5 W). Additionally, SPRINTER will deliver a 10 Gb/s burst-mode receiver with high dynamic range (>20 dBΩ) that will be combined with the widely tunable 10 Gb/s optical transceivers (see Objective 3). SPRINTER will also develop RF/IF/baseband units for the transmission and reception of mmWave signals at 73 GHz in real-time settings. The units will perform all the required functions at the physical layer, supporting operation with total bit rate up to 10 Gb/s. Additionally, SPRINTER will develop algorithms (software) and control electronics, including moderate-speed circuits (>10 MHz) that will drive the PZT-based phase actuators, low-speed circuits (<10 ms) that will drive the thermo-optic actuators, and bias circuits operating the gain chips, optical amplifiers, modulators and photodiodes.

Objective 6:
Develop a unified network platform that supports Time-Sensitive Networking over SDN infrastructure and enables reliable and real-time communication with guaranteed service quality

SPRINTER will deliver a software-defined networking (SDN) controller and agents to be integrated in the optical switch and radio components that would be managed as time-sensitive networking (TSN) bridges. SPRINTER will design the TSN Translator functionality for interoperation between wired and wireless TSN systems both for user plane and control plane. TSN translator functionality consists of Device-side TSN translator (DS-TT) and Network-side TSN translator (NW-TT). DS-TT and NW-TT optionally supports the following functionalities: i) Link layer connectivity discovery and reporting as defined in IEEE 802.1AB, ii) TSN configuration models defined in IEEE P802.1Qcc, iii) Centralized, Distributed or hybrid and iv) Interworking with TSN using IEEE 802.1Qbv based QoS scheduling. SPRINTER will implement the SDN controller that will manage the wired and radio components to deliver an ultra-reliable TSN infrastructure.

Objective 7:
Perform the physical and system integration of SPRINTER prototypes

SPRINTER will develop a set of methodologies and tools for the physical integration, packaging, and system integration of all prototypes, taking into account optical, electrical, thermal and mechanical issues. Using the building blocks outlined above (see objective 1-5), SPRINTER will develop the following prototypes: Module-1a will be a 4-fold InP-EML based optical transceiver that will provide 200 Gb/s aggregated capacity supporting the generation and detection of four 50 Gb/s OOK-NRZ signals. Module-1b will be a 4-fold GaAs-VCSEL based optical transceiver that will provide 200 Gb/s aggregated capacity supporting the generation and detection of four 50 Gb/s OOK-NRZ signals. Both prototypes will be mounted on printed circuit boards (PCBs) that will also host a 4-fold array of drivers and TIAs, and suitable RF connectors. Module-2a will be a 10 Gb/s optical transceiver based on an InP-TriPleX ECL, an LNOI MZM modulator, and an InP-PD, whilst Module-2b will be a 10 Gb/s optical transceiver based on the InP-TriPleX ECL, an InP-MZM modulator, and an InP-PD. Similarly, SPRINTER will develop low-speed PCBs to host the Module-2 optical subassemblies together with the 10 Gb/s burst-mode receivers. The high-speed control units will be connected to the optical subassemblies via proper RF interfaces. Module-3 will be an active 3D PolyBoard 32×32 SDM-ROADM. Finally, SPRINTER will provide two types of FSO/mmWave transceiver. The first one will be Module-4 Fixed Node (FN) that will be physically connected to an all-optical switching network, supporting FSO/mmWave high-capacity communication links towards Module-4 Remote Node (RN) that will be placed on a remote site. Within the final housing of each Module-4, the corresponding transceiver device and its control electronics will be co-packaged, electrically connected via high-frequency cabling and proper connectors. Special care will be taken for their mechanical stability and cooling within this housing.

Objective 8:
Evaluate the system performance of all prototypes and demonstrate the operation of SPRINTER system in realistic industrial environments

SPRINTER will evaluate the system performance of all prototypes using three main stages of system characterization. In the first stage, the optical modules will be tested in laboratory settings to assess their individual performance and validate their corresponding functionalities. In the second stage, the prototypes will be interfaced with fully operational end-hosts network interfaces cards (NICs) and will be integrated into the developed TSN-SDN hierarchy (see objective-6), to demonstrate the capabilities of SPRINTER architecture to support reliable and low latency communication with guaranteed service quality. Finally, SPRINTER will leverage the industrial facilities of FILL to demonstrate the SPRINTER architecture under realistic operational environments.

Objective 9:
Prepare solid roadmap and business plan for the commercialization and dissemination of SPRINTER technology

SPRINTER consortium will consolidate a solid strategy for the commercialization of the transceiver and switching technology developed within the project, and for the dissemination of the scientific outcome. There are three key points in this strategy. Market research: SPRINTER prototypes cover a broad range of applications and have been conceptualized based not only on the current needs of the industrial networks but also on the future needs in terms of flexibility and capacity. SPRINTER will review the targeted markets for each prototype, and perform market research to identify opportunities for fast commercialization after the project. Manufacturability plan: SPRINTER will perform manufacturability studies, identifying how the prototype’s cost can be further reduced through high-volume production. Promote European research excellence and deliver impact in standardization. SPRINTER will target to participate in top-ranked academic venues with high impact, in order to strengthen and promote the European research in photonic technologies for industrial applications. Additionally, SPRINTER will actively participate in the Time-Sensitive Networking Task Group (TG) that is a part of the IEEE 802.1 Working Group (WG).