Silicon photonics is a topic that draws much attention in the semiconductor industry. Even if mass production did not take off yet, there is a shared feeling that this technology will be full of promises. Silicon photonics is already addressing solutions in data-communication area and can potentially address new industrial segments such as long haul telecommunication cables, smart detectors, chemical sensors or even consumer products such as next generation computer peripheral cables. Consequently, STMicroelectronics is concentrating efforts in launching silicon photonic research activities that explore innovative solutions for future market demands. With a smart transition from discrete photonics to integrated photonics, ongoing developments in silicon photonics include the ability to co-integrate different materials within the same platform. Typically, epitaxially grown germanium is used to fabricate photodetectors. Moreover, a vast activity is also devoted at integrating III-V laser sources within the integrated circuit. Currently, various configurations are under evaluation to integrate a laser source within the silicon photonic chip. Furthermore, alternative non-metallic materials are also assessed to fabricate complementary passive devices. The rationale is to consider possible processes and designs to improve electrical power consumption budget, reduce optical transmission losses, achieve low cost production and introduce new functions within photonic systems.
Developments made in the framework of COSMICC European project aim at demonstrating few pJ/bit data transmission for a 4-channel coarse wavelength division multiplexing transceiver bearing a data rate of 56 Gbps NRZ per channel. The demonstrator will make use of current and projected developments made by both STMicroelectronics and collaborators.