To advance its objectives, Next-2Digits structured its work into five technical Work Packages (WPs).
WP1 – Requirements and Specifications:
The project reviewed existing system specs and proposed enhanced ones tailored to the needs of each application, prioritising factors like size for LIDAR, response time for greenhouse gas sensing, and spectral response for OCT. Tailored requirements for the three demonstrators were successfully defined, along with PIC design choices.
WP2 – 2D Materials Growth and Platform Development:
GSEMI supplied various graphene donor substrates to NTUA, which conducted DFT-based quantum-mechanical simulations to study graphene behaviour on receiver substrates and detachment processes from metallic donors. VTT optimised optical mode simulations for detector integration. First-generation 2D material and SOI platform qualification tests were completed, and initial wafer processing for graphene integration was successfully conducted by SILEX and VTT.
WP3 – 2D Material Digital Transfer and Integration:
NTUA began developing a laser direct transfer (LDT) station to meet graphene photodetector needs. The LIFT method was demonstrated as a fast, low-cost way to integrate 2D materials onto chips. Arrays of graphene pixels were successfully transferred and integrated into photodetector prototypes, now under evaluation by VTT. Material integrity was validated using advanced microscopy and spectroscopy techniques. GSEMI also achieved semi-dry monolayer graphene transfers on multiple 8-inch wafers from SILEX and on planarized wafers from VTT.
WP4 – 2DM Component and PIC Fabrication:
Initial efforts involved short-loop definitions and mask design/testing for the three use cases. For the LIDAR sensor, SILEX and OMMA are optimising the waveguide platform. For the greenhouse gas sensor, SENSE ran simulations to define suitable waveguide dimensions and designed structures for testing key components. For the PDR, VTT and G&H collaborated on design specs and developed integration components for aligning light intensity with graphene detectors. Initial integration of graphene detectors is completed.
WP5 – Use Cases Integration and Validation:
This WP focuses on integrating and validating each use case.
• Use Case 1: Ground-based tests using an existing YSCAN system confirmed accurate trajectory reconstruction via SLAM and GNSS-Inertial fusion. Development is ongoing.
• Use Case 2: Preparations are underway, including coordination among SENSE, LiU, and BERT, and procurement of necessary equipment and materials.
• Use Case 3: G&H began testing and validation for PDR devices. Test setups for fibre-chip coupling have been optimized, and optical arrays were sourced to evaluate multiple outputs simultaneously.
