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

Parallelizable Microfluidic Resistive On-Line Detector of Micrometric Aggregates of Biopharmaceutical Antibodies

A microfluidic device based on the differential measurement of the ionic resistance of a micropore for detection of aggregates of antibodies in biopharmaceutical downstream process is presented. The main novelty of this contribution regards the experimental demonstration that, despite the poor solidness of proteins, their aggregates, in their standard production buffer, can be electrically detected down to 2.4 μm diameter with sub-ms transit time (flow rate of 5 μl/min). Thanks to the simple PDMS fluidic fabrication, compact DC readout circuit and convenient use of the same metallic silver tubing for both electrical and fluidic interconnection, the device can be straightforwardly parallelized in tens of units, thus combining single micrometric sensitivity with larger flow rates (>100 μl/min), suitable for in-line installation in pharmaceutical plants

Time Dependent Inelastic Emission and Capture of Localized Electrons in Si n-MOSFETs Under Microwave Irradiation

Microwave irradiation causes voltage fluctuations in solid state nanodevices. Such an effect is relevant in atomic electronics and nanostructures for quantum information processing, where charge or spin states are controlled by microwave fields and electrically detected. Here the variation of the characteristic times of the multiphonon capture and emission of a single electron by an interface defect in submicron MOSFETs is calculated and measured as a function of the microwave power, whose frequency of the voltage modulation is assumed to be large if compared to the inverse of the characteristic times. The variation of the characteristic times under microwave irradiation is quantitatively predicted from the microwave frequency dependent stationary current generated by the voltage fluctuations itself. The expected values agree with the experimental measurements. The coupling between the microwave field and either one or two terminals of the device is discussed. Some consequences on nanoscale device technology are drawn.Comment: 8 Figure

Automated routing and control of silicon photonic switch fabrics

Automatic reconfiguration and feedback controlled routing is demonstrated in an 8×8 silicon photonic switch fabric based on Mach-Zehnder interferometers. The use of non-invasive Contactless Integrated Photonic Probes (CLIPPs) enables real-time monitoring of the state of each switching element individually. Local monitoring provides direct information on the routing path, allowing an easy sequential tuning and feedback controlled stabilization of the individual switching elements, thus making the switch fabric robust against thermal crosstalk, even in the absence of a cooling system for the silicon chip. Up to 24 CLIPPs are interrogated by a multichannel integrated ASIC wire-bonded to the photonic chip. Optical routing is demonstrated on simultaneous WDM input signals that are labelled directly on-chip by suitable pilot tones without affecting the quality of the signals. Neither preliminary circuit calibration nor lookup tables are required, being the proposed control scheme inherently insensible to channels power fluctuations

Microwave Irradiation Effects on Random Telegraph Signal in a MOSFET

We report on the change of the characteristic times of the random telegraph signal (RTS) in a MOSFET operated under microwave irradiation up to 40 GHz as the microwave field power is raised. The effect is explained by considering the time dependency of the transition probabilities due to a harmonic voltage generated by the microwave field that couples with the wires connecting the MOSFET. From the dc current excited into the MOSFET by the microwave field we determine the corresponding equivalent drain voltage. The RTS experimental data are in agreement with the prediction obtained with the model, making use of the voltage data measured with the independent dc microwave induced current. We conclude that when operating a MOSFET under microwave irradiation, as in single spin resonance detection, one has to pay attention into the effects related to microwave irradiation dependent RTS changes.Comment: 3 pages, 4 figure

“♥ is in the air”: the expansion of the image of the heart in the contemporary urban and digital landscape

La imagen del corazón aparece constantemente en nuestro día a día: la encontramos en la decoración de multitud de objetos cotidianos, en la ropa, en las pintadas callejeras, en logotipos y escaparates, y es omnipresente en el mundo digital, donde el comando “me gusta” tiene a menudo forma de corazón. El presente trabajo tiene el objetivo de identificar las razones de esta predilección por la imagen cardíaca y las funciones que desempeña su representación. Para ello, hemos llevado a cabo un estudio de paisaje lingüístico y semiótico, recopilando y analizando un amplio corpus de imágenes de corazones, recogido en el espacio urbano y en internet. El análisis muestra que la imagen estudiada desempeña todas las funciones del lenguaje de Jakobson (1984); los principales contextos de uso del corazón son la expresión del sentimiento amoroso, la muestra de apreciación y la manifestación de agradecimiento. Comentamos en las conclusiones el “trasvase” de usos del corazón de la calle a la pantalla y viceversa.The image of the heart regularly appears in our daily lives: it decorates multiple everyday objects, such as clothing, logos, shop windows, and it appears on graffiti. Additionally, it is ubiquitous in the digital world, as the "like" button is often in the shape of a heart. The aim of this paper is to identify the reasons why the image of the heart is so widespread, and the functions performed by its representation. In order to do so, we carried out a linguistic and semiotic landscape study, by analysing a large corpus of images of hearts, collected in the urban landscape and on the Internet. The results show that the hearts found in the two corpora perform all language functions identified by Jakobson (1984); the main contexts of use of the heart are the expression of love, appreciation, and gratitude. Finally, we comment on the "transfer" of functions of the heart from street to screen and vice versa