Photonic System Engineering with Microcombs

Project Information

MicrocombSys

Grant agreement ID: 101119968

DOI

10.3030/101119968

EC signature date 26 June 2023

Start date 1 October 2023

End date 30 September 2027

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 2 788 624,80

Coordinated by

CHALMERS TEKNISKA HOGSKOLA AB
Sweden

Periodic Reporting for period 1 - MicrocombSys (Photonic System Engineering with Microcombs)

Reporting period: 2023-10-01 to 2025-09-30

Summary of the context and overall objectives of the project

The MicrocombSys Doctoral Network aims to advance the scientific, technological, and industrial foundations for chip-scale optical frequency combs (microcombs), a key enabling technology for next-generation communication systems, precision metrology, LiDAR, quantum technologies, and mid-IR spectroscopy. The project brings together 12 doctoral candidates across European universities, research institutes, and industrial partners to address the full microcomb value chain: novel material platforms, active amplification, photonic–electronic integration, scalable packaging, and system-level demonstrations in real-world applications.
Its overall objectives are to (1) develop advanced microcomb platforms with enhanced nonlinear functionality, (2) create heterogeneous integration and packaging technologies for active–passive photonic co-integration, (3) validate microcomb engines in strategic applications, and (4) deliver a comprehensive training and career development program for early-stage researchers. The work in the first 24 months has proceeded well in line with the Description of Action.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

WP1 advanced material platforms and active components for integrated microcombs. Silicon nitride photonic-molecule microcombs were designed and fabricated; SiGe resonators achieved Q-factors up to 10⁶ for mid-IR combs; SiC chips demonstrated stable 450-nm soliton generation; and EPFL realised a wafer-scale Er:Si₃N₄ amplifier showing >8 dB net gain and >180 mW output power. Rare-earth implantation workflows, Ti:Sapphire chiplet integration, and novel dispersion-engineered waveguide designs further strengthened the component-level toolkit.
WP2 achieved major progress toward heterogeneous integration and packaging. A validated laser–PIC opto-electrical packaging route was demonstrated and tolerance-optimised. Electro-optic wavelength-management components on lithium tantalate reached publication stage. First-generation packaging building blocks for microcomb engines were realised, establishing low-loss, thermally stable integration strategies. Quantitative modelling tools for microcomb-based coherent transmitters were developed in collaboration with industry, paving the way for multi-channel hardware integration.
WP3 delivered application-level validation. A record 100-Pbit/s data-transmission experiment based on a single microcomb was demonstrated. New SiGe/Ge resonator structures for MIR dual-comb spectroscopy were designed; visible–UV waveguides for biological imaging were explored; and the first thin-film lithium-niobate quantum pulse-gate prototype was fabricated. EPFL and Blickfeld completed a high-speed FMCW LiDAR demonstrator using frequency-agile photonic integrated lasers. Application-oriented packaging and material advances (e.g. AlN, Ti:Sapphire, SiC) were further leveraged across tasks.
WP4 delivered two technical courses, two workshops, and the first annual conference. All DCs have active Personal Career Development Plans, and a series of webinars has been launched.
WP5 supported innovation management and IP protection, with two patent applications under preparation.
WP6 ensured strong dissemination and public engagement through the project website, LinkedIn page, eight international conference participations, four publications, and outreach events such as the International Day of Light 2025.
WP7 ensured smooth management, with all deliverables submitted on time and coordination bodies operating as planned. One DC withdrew due to personal reasons, and the position has been re-advertised.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The project has already produced several advances that significantly exceed the state of the art:
• Active microcomb platforms:
o Demonstration of a wafer-scale erbium-doped Si₃N₄ amplifier with >8 dB net gain and 180 mW output power—among the highest reported for planar EDWAs and directly relevant to on-chip soliton amplification.
o First stable soliton generation in SiC microresonators using a thermally compensated scheme, enabling dual χ(2)/χ(3) nonlinear platforms for self-referenced microcombs.
• High-Q and broadband nonlinear resonators:
o SiGe devices reaching Q-factors up to 10⁶ for MIR microcomb generation represent a major step toward integrated broadband sensing.
• Heterogeneous integration innovations:
o The first validated packaging workflow integrating high-power lasers with Si₃N₄ PICs enables scalable microcomb module manufacturing.
o Thin-film lithium tantalate AWGs demonstrated high uniformity and low insertion loss, enabling advanced spectral shaping for LiDAR and communication.
• Application breakthroughs:
o A 100-Pbit/s experiment using a single integrated microcomb showcases the disruptive potential of microcombs for ultra-high-capacity communications.
o A functional FMCW LiDAR demonstrator based on frequency-agile integrated lasers marks a decisive step toward field-deployable microcomb-based sensing.
These results push microcomb technology closer to practical deployment and strengthen Europe’s position in nonlinear integrated photonics.