Since the project's launch, the CombTools partners have focused on four key activities. First, we have defined the concepts and specifications for the first generation of comb sources and auxiliary subsystems, tailored to meet the requirements of the application demonstrations. Second, we have fabricated Si₃N₄ chips for soliton microcomb generation, which will be packaged in RP2 and later distributed to partners for system-level demonstrations. In parallel, we have worked on the design, fabrication, and characterization of the auxiliary subsystems required to integrate the combs into complete systems. Third, we have begun preparations for the demonstration of comb-based free-space optical (FSO) transmission at Eindhoven, defining the initial specifications of the testbed and characterization setup. Finally, as part of the project’s dissemination efforts, we have participated in trade shows to explore market opportunities for comb technologies, assess industry demand, and evaluate potential commercialization pathways. This comprises a first commercial offering of known-good comb dies that Deeplight is currently establishing.
In the first reporting period, the collaborative efforts of the partners have led to the following highlight results:
• Data transmission at record-high symbol rates using comb-based optical arbitrary waveform generation and measurement (OAWG/OAWM): KIT has implemented schemes for optical arbitrary waveform generation and measurement (OAWG/OAWM) at bandwidths of hundreds of gigahertz. In a collaborative effort with NBL, these schemes were used for long-haul data transmission at record-high single-channel data rates of up to 2.7 Tbit/s. We further demonstrated transmission of single-channel data rates of 1.6 Tbit/s over transatlantic distances. These results were presented at the European Conference of Optical Communications (ECOC) 2024 and subsequently included in a journal publication that is currently under review at the Journal of Lightwave Technology (JLT).
• Advanced fabrication process: EPFL developed a copper-free photonic Damascene Si₃N₄ fabrication process, enhancing performance and scalability with sub dB/m loss.
• World-class testbed: TUE established a cutting-edge FSO testbed with terabit-class data transmission capabilities, providing a crucial platform for further experimentation and validation.
• First commercial offering of die-level Kerr comb generators: DLT is about to establish a commercial offering of known-good die-level comb generators. This is a first step towards thereby “democratizing” chip-scale frequency comb technology and preparing the ground for a wide range of follow-up innovations.
