Photonics is a rapidly growing sector in the global economy. Optical communications, optical storage, imaging, lighting, optical sensors or security are just a few examples. Even if photonics could bring improved characteristics to electronic components as low propagation losses, high bandwidth, wavelength multiplexing and immunity to electromagnetic noise, the high cost of photonic components and there assembly is a major obstacle to their deployment in most of application fields. Yet, just like in micro-electronics, many applications can be realized in a much more compact and cost-effective way by integrating the required functionality in a single chip.
Silicon photonics (or more precisely CMOS Photonics) is a way to tackle the problem of integration by developing a small number of generic integration technologies with a level of functionality that can address a broad range of applications. Such technologies, which should be made accessible via foundries, can address markets that are sufficiently large to pay back the development costs.
As in microelectronics, the key for the success of integration in photonics is to realize a broad range of optical functionalities with a small set of elementary components, and to develop a generic wafer-scale technology for integration. This generic technology will most likely not wipe away more specialized custom technologies but will create new opportunities for a much larger deployment of photonic ICs. Since the single device (e.g. laser/modulator/etc...) will have an insignificant cost, the designers will concentrate on the way to achieve the desired functions by using as many components as needed.
Moreover, by co-integrating optics and electronics on the same chip, high functionality, high performance and highly integrated devices can be fabricated, while using well mastered microelectronics fabrication process. Another advantage of CMOS photonics is that its success will move the emphasis from the component to the architecture. In other words, industrial and RTD efforts could be focused on new products or new functionalities rather than on the technology level.
However, there are many challenges and issues to be addressed before bringing Photonics on CMOS at a mature industrial level. In particular, photonics integration must be straightforward for IC designers and manufacturers. That means that CMOS compatibility is mandatory, as well as the creation of design tools and libraries compatible with IC standards
At this moment, these conditions have been fulfilled neither through research laboratory demonstrations nor through industrial realisations.
Proof of concept or functional demonstrations of major building blocks have been made in previous research projects (laser, modulator, detector, coupling, and link). To go one step further, the European CMOS Photonics community must demonstrate the integration of photonics with electronics and make available an integrated design and fabrication chain with standard and generic processes that could be transferred to foundries.