Since light is already the backbone of telecommunications worldwide, one of the most urgent breakthroughs that need to be achieved involves the accomplishment of higher speed and data rates using devices of low energy consumption and fabrication cost. For such a task, complementary metal-oxide-semiconductor (CMOS) fabrication processes have a clear advantage over other proposed technologies owed to their compatibility with large volume production and the deep knowhow in implementing ultra-compact optoelectronic chips. Within this technology, a viable solution for higher data-rate transmission with reasonable costs is the multiplication of parallel channels through wavelength division multiplexing (WDM). In principle silicon photonics has all the key building blocks for such a task and has already delivered commercial solutions for data centers by exploiting four optical carriers, each one relying on a different III-V laser. However, this solution cannot be considered as viable for devices that would need to operate with to tens or even hundreds of wavelength channels simply because it would require a large number of lasers sources, very complicated integration protocols and of course more power.
In this context, the FOIST project is devoted to the emerging field of low power, compact and high bandwidth on-chip optical communications. It aims at developing a new technological approach based on the combination of functional oxides and silicon photonics to address the development of amplified frequency comb sources in the C-band (1535nm-1565nm). The innovative concept is based on the use of a single pump source to simultaneously generate and amplify multiple coherent and equidistant channels. This project will explore a new approach to exploit the high Kerr nonlinear refractive index coefficient, negligible nonlinear loss and versatile material engineering of rare-earth doped functional oxides for the realization of multi-wavelength amplified Kerr emitters in a silicon photonics platform. The state of the art in this field mainly uses r silicon and silicon nitride to develop Kerr optical frequency combs. The efficiency of the Si Kerr frequency comb is hindered by one major drawback: strong nonlinear loss due to two photon absorption (TPA). Furthermore none of these solutions can provide any amplification of the output channels.
By merging the skills of three academic partners (C2N, IOGS-LCF and IPREM-UPPA) and one industrial partner (STMicroelectronics), major player in silicon photonics, the consortium will develop advanced multi-wavelength TBit/s photonics circuit on Si platform. The project heavily relies on three main cornerstones that have been preliminary investigated by the partners. These are, thefirst measurement on Kerr optical response of the YSZ material by C2N and IOGS-LCF, the achievement of light propagation on waveguides integrated on silicon by C2N and the accomplishment of strong photoluminescence properties in Er:YSZ films by C2N). The main objectives of the FOIST project target to bring new knowledge about theoretical aspects of the Kerr nonlinear optical response of functional oxides which is largely unknown. The demonstration of state-of-the-art hybrid frequency comb generation sources and on-chip light amplification based on rare-earth doped functional oxides integrated on silicon platforms. The full integration of both source and amplifier with other Si building blocks will be addressed, thanks to the cross work to be achieved with STMicroelectronics. The scientific and technical outputs will be published in highly sighted international peer reviewed scientific journals, presented at relevant conferences. Moreover the knowhow to be gained will participate to the visibility of the upstream research of STMicroelectronics to its customers. Finally, the device concept is expected to lead to IP through joint patents between involved academic partners and STMicroelectronics.
Monsieur Philippe Lecoeur (Centre de Nanosciences et de nanotechnologies (C2N))
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
LP2N Laboratoire Photonique, Numérique, Nanosciences
IPREM INSTITUT DES SCIENCES ANALYTIQUES ET DE PHYSICO-CHIMIE POUR L'ENVIRONNEMENT ET LES MATERIAUX
C2N Centre de Nanosciences et de nanotechnologies (C2N)
Help of the ANR 580,139 euros
Beginning and duration of the scientific project: June 2019 - 42 Months