The research on Wireline and Optical circuits at MICAS is pushed by the never-ending need for energy efficiency, higher speeds, and lower latency. But at the same time, MICAS also explores innovative communication concepts such as full-silicon optical solutions enabling 1310/1550 nm communication and polymer microwave fibers (PMF).
Optical interaction is highly challenging in silicon. The high doping concentrations and low supply voltages of CMOS result in small and slow responses of photodiodes. Moreover, 1310/1550 nm light is not absorbed due to the high bandgap. However, the trend towards higher integration levels can also be seen in this challenging domain thanks to innovative circuit techniques combined with novel conversion mechanisms between the optical and electrical domains. MICAS has been a trendsetter in this domain for many years.
Also, with respect to polymer microwave fibers, MICAS stays in the leading position by pushing the boundaries in terms of data rate and distance. Not only is the research investigating Silicon integrated frontends for PMF but also couplers, duplexers and fibers are being investigated to obtain the optimal solution for a wide range of connectivity applications.
MICAS has developed several generations PMF demonstrators. These demonstrators show the benefits and limitation of PMF compared to copper wireline and optical communication systems. Both long-reach (~10m) and short reach (10cm) solutions are being investigated, designed, fabricated and measured.
MICAS has pioneered fully integrated optical receivers for many years. Starting with integrated pn-photodiodes optimized for speed and responsivity, we are now investigating using Schottky photodiodes to detect longer wavelengths typically used in optical communication links. We are investigating how to increase the sensitivity and speed while reducing the power consumption of such receivers. Also, we are exploring using this concept for other applications beyond data communication.