Periodic Reporting for period 3 - PIX4LIFE (Silicon Nitride Photonic Integrated Circuit Pilot line for Life Science Applications in the Visible Range)
Reporting period: 2018-07-01 to 2020-09-30
The PIX4life ambition was to mature a high performance, high yielding SiN Photonic IC pilot line together with the accompanying supply chain for applications in the visible range (400-1000 nm) in order to become the world’s premier pilot line for multitype integrated biophotonic applications.
Now, PIX4life is the European pilot line that offers an open-access manufacturing platform for photonic integrated circuits. The PIX4life silicon nitride photonic platform is ideally suited to develop products that require visible light or slightly higher wavelengths (400-1100 nm), making this platform interesting to a broad range of industrial customers active in the life science domain or beyond. Besides the manufacturing, PIX4life has an attractive website and accompanying gateway in place to enable customers to easily find their way to the offering, supported with photonic knowhow and design and testing expertise. Not only having this supply chain is key, also education of the target field is of utmost important to make sure SiN technology will be widely adopted. In that respect ePIXfab, a not-for-profit open alliance of academic and industrial organizations with a mission to promote silicon photonics science, technology and applications is offering training activities for the PIX4Life pilot line.
Both foundries, imec and LioniX optimized their BioPIX and TriPleX platforms, respectively. Both platforms are ideally suited to develop visible light applications as demonstrated by e.g; the use case partners in the PIX4life project and customers of the pilot line that developed life science applications.
2. Improved accessibility to the technology, by developing an end-to-end supply chain reaching from design to packaged and characterized chip components.
PIX4life has set up an end-to-end supply chain, including design –manufacturing- photonic testing and packaging (this latter one in close collaboration with the PIXAPP pilot line)
3. Demonstration of the potential of the SiN photonics technology by realizing complex photonic ICs meeting the application driven specifications for miniaturized biosensors, optical coherence tomography imagers, multispectral sources for microscopy, and point of care cytometry.
In the PIX4life project, 4 inspiring demonstrator cases were chosen. An OCT on-chip demonstrator has been successfully implemented. The OCT system was able to detect (artificial polymer based-) tissue with a SNR of around 20dB.
• The Multi-DOF-sensor shows the high sensitivity of silicon photonic sensors, but the development of functional ion-sensitive layers showed not to be straightforward. However, based on a similar PIC implementation a proof-of-concept demonstration of an integrated refractive index gas sensor for environmental safety monitoring with detection limit in the sub-ppm level was achieved.
• Two different types of multispectral light sources have been implemented.
• A module, including a light source with the pattern generation PIC, a beam shaping lens system, and the sample flow sub-assembly have been integrated with light collection optics for the full cytometric application demonstration.
4. build and validate an open access model for customers internal and external to the consortium with the aim to lower barriers to entry for European companies, SME’s and universities to test and validate photonic concepts in the visible range.
5 MPW runs were organized with early access users. The services are accessible for the customers via the PIX4life website (gateway operated by VLC photonics), via Europractice and the two foundries (imec and LioniX).
Building blocks: There was already a vast knowlegde on passive components and building blocks in telecom wavelength regime, mainly for silicon but also for silicon nitride. The visible frequencies ware much less developed. Besides passive components many applications require modulators to switch and modulate the light on the chip. Here less building blocks were available. As such during PIX4life 162 building blocks were designed in BIOPIX (80) and TriPlex (82) technology with wavelengths covering the full visible and very near IR.
Design tools: The Design tools of partner Synopsis and Luceda were in place at the start of the project to design on both the TripleX and BioPIX platforms. Early process design rules for both technologies are available but lack standardization of both the technologies and the building blocks. In the PIX4life project further work has been invested to standardize these photonic components as photonic building blocks libraries.
Integration options: Integration and packaging of photonic devices remains a hurdle to the commercialization of photonic based chip technologies. Several partners in the project made major progress in source integration with SiN. The flip chip edge coupling of external cavity lasers to waveguides was demonstrated by RWTH Aachen, Toptica and imec. Chalmers and Tyndall developed the hybrid integration of angled flip-chipped VCSELs onto PICs with appropriately designed grating couplers and demonstrated a potentially viable process. Chalmers has worked with imec on the development of VCSELs for micro-transfer printing on the PIX4life SiN waveguide platform