Optoelectronics and microwave photonics: high-speed optical modulators, IR and UV detectors, LEDs
The research group has been involved since 1990 in the modeling and simulation of high-speed modulators and detectors for 10 and 40 Gbps systems, and in the analysis and design of vertical-cavity surface-emitting lasers (VCSELs).
The main subjects in the modulator area have been the electromagnetic modeling of traveling wave lithium niobate Mach-Zehnder modulators, their design and system-oriented modeling; the physics-based, EM and system-oriented modeling of electroabsorption and electrooptic modulators on semiconductor substrates, and the experimental electro-optic characterization up to 40 GHz of electrooptic and electroabsorption modulators; the modeling, optimization and design of pin photodiodes for 10 Gbps systems and of distributed, traveling-wave photodetectors for microwave photonic applications.
The group has developed a full set of EM and physics-based analysis tools for the design and simulation of modulators and receivers on semiconductor and piezoelectric substrates. The activities have involved cooperations with several industries (Pirelli Optical Components, Corning, Avanex, Pirelli Labs, Agilent, Cisco) and the participation to national and international research projects (Madess II, EpixNet). There is a standing cooperation with Istituto Superiore Mario Boella (ISMB) through the joint DET-ISMB laboratory Photonlab, hosting some of the experimental activities described in this section.
In connection with the research line on the modeling of advanced semiconductor materials, the group has recently started (with Boston University) a research activity on HgCdTe APDs and detectors for multiple wavelengths. UV APDs and LEDs, both GaN- and ZnO-based, are also actively researched in cooperation with groups at Boston University and Università di Padova. The optimization of all such devices takes advantage from the group’s ability to accurately model e.g. the impact ionization and Auger recombination mechanisms in these narrow- and wide-gap material systems.