arXiv subjects

Andrea Melloni

Publications and source records attributed to Andrea Melloni.

24 records · Page 2Linked to original sources

arXiv2015

Design of a hybrid silicon-plasmonic co-propagant integrated coherent perfect absorber

By a hybrid integration of plasmonic and dielectric waveguide concepts, it is shown that coherent perfect absorption can be achieved in a co-propagant coupler geometry. The device holds promises for classical and quantum signal processing. First, the operating principle of the proposed device is detailed in the context of a more general 2x2 lossy coupler formalism. Then, it is shown how to tune the device in a wide region of possible working points, its broadband operation, and the tolerance to fabrication uncertainties. Finally, a complete picture of the electromagnetic modes inside the hybrid structure is analyzed, shining light onto the potentials which the proposed device holds in view of other applications like nonlinear optics, polarization control, and sensing.

physics.optics↗

arXiv2014

ContactLess Integrated Photonic Probe for light monitoring in InP-based devices

The increasing complexity of photonic integrated circuits requires the possibility to monitor the state of the circuit in order to stabilize the working point against environmental fluctuations or to perform reliable reconfiguration procedures. Although InP technologies can naturally integrate high-quality photodiodes, their use as tap monitors necessarily affects the circuit response and is restricted to few units per chip. They are hence unsuited for very large circuits, where transparent power monitors become key components. In this paper we present the implementation of a ContactLess Integrated Photonic Probe (CLIPP) realizing a non invasive integrated light monitor on InP-based devices. We describe an innovative vertical scheme of the CLIPP monitor which exploits the back side of the chip as a common electrode, thus enabling a reduction of the device footprint and a simplification of the electrical connectivity. We characterize the response of the CLIPP and demonstrate its functionality as power monitor. Lastly, we provide a direct demonstration that CLIPP monitor allows to access more accurate information on the working point of photonic integrated circuits compared to conventional external or integrated photodetectors.

physics.optics↗

arXiv2014

Non-invasive monitoring and control in silicon photonics by CMOS integrated electronics

As photonics breaks away from today's device level toward large scale of integration and complex systems-on-a-chip, concepts like monitoring, control and stabilization of photonic integrated circuits emerge as new paradigms. Here, we show non-invasive monitoring and feedback control of high quality factor silicon photonics resonators assisted by a transparent light detector directly integrated inside the cavity. Control operations are entirely managed by a CMOS microelectronic circuit, hosting many parallel electronic read-out channels, that is bridged to the silicon photonics chip. Advanced functionalities, such as wavelength tuning, locking, labeling and swapping are demonstrated. The non-invasive nature of the transparent monitor and the scalability of the CMOS read-out system offer a viable solution for the control of arbitrarily reconfigurable photonic integrated circuits aggregating many components on a single chip.

physics.optics↗

arXiv2013

Non-invasive light observer

Photonic technologies lack non-invasive monitoring tools to inspect the light inside optical waveguides. This is one of the main barriers to large scale of integration, even though photonic platforms are potentially ready to host several thousands of elements on a single chip. Here, we demonstrate non-invasive light observation in silicon photonics devices by exploiting photon interaction with intra-gap energy states localized at the waveguide surface. Light intensity is measured through a ContactLess Integrated Photonic Probe (CLIPP) that introduces no measurable extra-photon absorption and a phase perturbation as low as 0.2 mrad, comparable to thermal fluctuations of less than 3 mK. Multipoint light monitoring is demonstrated with a sensitivity of -30 dBm and a dynamic range of 40 dB. CLIPP technology is simple, inherently CMOS compatible, and scalable to hundreds of probing points per chip. This concept provides a viable way to real-time conditioning and feedback control of densely-integrated photonic systems.

physics.optics↗

arXiv2013

Comment on "Linear and passive silicon optical isolator" in Scientific Reports 2, 674

Wang et al. [1] demonstrated different power transmission coefficients for forward and backward propagation in simulation and experiment. From such a demonstration, the central claim of their paper is that "the spatial inversion symmetry breaking diode can construct an optical isolator in no conflict with any reciprocal principle". Their claim contradicts the Lorentz reciprocity theorem, from which it is well known that one cannot construct an isolator this way.

physics.optics↗

arXiv2011

Comment to "Nonreciprocal Light Propagation in a Silicon Photonic Circuit"

In the article "Nonreciprocal Light Propagation in a Silicon Photonic Circuit" (Science 333, 729-733 (2011) a nonreciprocal waveguide system based on a combination of silicon, dielectrics and metals is reported. In this Comment it is explained that the interpretation with respect to nonreciprocity in this paper is incorrect and conflicts with the fundamental Lorentz reciprocity theorem. It is further pointed out that a previous publication already introduced the device concept.

physics.optics↗