Roberto R. Panepucci

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Photonic circuits, in which beams of light redirect the flow of other beams of light, are a long-standing goal for developing highly integrated optical communication components. Furthermore, it is highly desirable to use silicon--the dominant material in the microelectronic industry--as the platform for such circuits. Photonic structures that bend, split,(More)
We experimentally demonstrate a novel silicon waveguide structure for guiding and confining light in nanometer-wide low-refractive-index material. The optical field in the low-index material is enhanced because of the discontinuity of the electric field at high-index-contrast interfaces. We measure a 30% reduction of the effective index of light propagating(More)
We propose and demonstrate an efficient coupler for compact mode conversion between a fiber and a submicrometer waveguide. The coupler is composed of high-index-contrast materials and is based on a short taper with a nanometer-sized tip. We show that the micrometer-long silicon-on-insulator-based nanotaper coupler is able to efficiently convert both the(More)
We present an experimental demonstration of fast all-optical switching on a silicon photonic integrated device by employing a strong light-confinement structure to enhance sensitivity to small changes in the refractive index. By use of a control light pulse with energy as low as 40 pJ, the optical transmission of the structure is modulated by more than 97%(More)
A set of low noise transimpedance amplifiers fabricated and characterized in CMOS and BiCMOS technologies are proposed in this work. Layout optimization, efficient modeling and bias point optimization are the techniques employed to reduce the input noise current density. The CMOS amplifiers were designed to work at 10 Gbps. The BiCMOS amplifiers, based on(More)
Design guide lines are given for developing SiGe HBT mm-wave d.c. coupled ultra-wide-band low noise monolithic amplifiers. An ultra wide band LNA and two mm-wave TIAs for 40 Gbps and 100 Gbps applications are proposed. The LNA has S21=11 dB and a 3-dB bandwidth of 88 GHz. The 40 Gbps TIA has a new topology, allowing a DC coupled performance, 54 dBΩ(More)
The regulated cascode (RGC) is a widely used topology in transimpedance amplifiers projects. Although it is efficient with respect to power consumption and bandwidth, the regulated cascode presents high input-referred current noise levels that hinder the use of this topology in long distance optical networks. In this paper is proposed a design methodology(More)
This work aims to establish and validate the current methodology of design and process of microfabrication of polymer-based neural probes with planar microelectrodes, both to record and stimulate neuronal activity in animal models of epilepsy. SU-8 was chosen as structural material due to its good electromechanical properties, and biocompatibility, which(More)
In this work, we describe a system in which a thermally tunable micro-ring resonator filter is applied to monitor spectral shifts in a FBG sensor. The system was simulated using the time interval method with a simple ring resonator thermo-optical model with experimental values. For 2.56 nm scan range at 1 Hz we predicted a time interval sensitivity of 124(More)
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