The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We report on the fabrication and characterization of a near infrared junction field effect phototransistor provided with a Germanium gate and fabricated in a silicon photonics foundry. The maximum device responsivity exceeds 36A/W with a dark current of 33µA at 2V.
Laser assisted keratoplasty is largely used to perform minimally invasive surgery and partial thickness keratoplasty (PTK) [1–3], which can be performed through several different techniques. Such approaches are eligible with respect to the standard penetrating keratoplasty and would benefit a major comprehension of the deep stroma layers morphology, which would be crucial in identifying the correct...
In this paper we report an integrated phase modulator based on two layers of graphene on top of a SOI waveguide. Biasing the graphene to the transparency condition we show that is possible to achieve phase modulation with promising performance in terms of efficiency and insertion losses with respect to the conventional pn junction silicon phase modulators. The proposed device exhibits an efficiency...
The combination of our protocol with optical systems similar to the one described, makes it possible to study regulatory processes in bacteria that are dependent on the spatial distribution of genes and other cellular components.
We have proposed a novel SH coherent system based on direct modulation of the laser source to generate the signal and the carrier (operating as LO) co-propagating in the fiber. At the RX just direct detection is employed, without the necessity of SOP tracking to separate the carrier and the signal. Double transmission capacity is achieved with about 3-dB gain in performance with respect to 4-PAM modulation...
Multipath interference (MPI) in bend-insensitive fibers (BIFs) has been investigated to quantify its effect in access networks that are being installed in curbs and buildings. Two measurement setups have been evaluated, highlighting the related measurement issues like the intrinsic polarization dependent loss (PDL) that sets the measurement sensitivity. An optimized measurement setup has been realized...
SiPM performance depends on the cell layout, gain and semiconductor properties. We improved the performance of FBK NUV SiPM acting at a technological level and at a cell structure level. A new substrate with reduced minority carrier lifetime strongly reduces the probabilities of delayed crosstalk and diffused afterpulsing. Moreover, thanks to a redesigned border structure, with trenches between cells,...
In this paper we describe a promising approach to increase the output energy of a laser system emitting infrared radiation in the spectral range 6.78µm based on direct difference frequency generation in non-oxide nonlinear crystals using single-mode Nd:YAG laser and tunable Cr:forsterite laser, which was developed for the muonic-hydrogen experiment.
In this work we applied a single molecule technique to investigate an intriguing biological problem not yet fully understood. We used a novel approach capable to measure with unprecedent spatial and temporal precision the interaction between proteins and DNA, allowing us to determine the position of both specific and unspecific interaction along the DNA filament.
In this work the impact of the fabrication non-idealities on the reflection features of dielectric high-contrast gratings (HCGs) is discussed. The grating performance is quantified considering the plane-wave scattering problem. This is solved by means of a novel full-wave simulator based on the mortar element method. The flexibility of this scheme is exploited to obtain a realistic model of a HCG...
We propose four strategies to establish the operation of the transmitter of flexible modulation formats based on different PAM constellations on the in-phase and quadrature axes of the two polarizations exploited for optical fiber transmission (Flex-PAM). We verify that the strategy based on forcing all the four PAMs to operate at the same bit error rate (BER) - the “same-BER” strategy - besides being...
Solar panels in both space (satellites) and earth applications have a fundamental problem related to their pointing with a right angle towards the sun. In fact, a correct pointing of the sun could improve energy efficiency produced by the panels. In this paper, with the aim to obtain a solar concentrator, we present the realization of Volume Holographic Optical Elements (V-HOEs), such as holographic...
In this paper, with the aim to realize a nonlinear microscope based on Coherent Raman Spectroscopy, we describe the implementation of femtosecond stimulated Raman scattering technique as a first step, i.e. single pixel, towards nonlinear microscope. Details of experimental set up and the main issue for experimental implementation of femtoseconds CRS spectroscopy are discussed. Finally, Stimulated...
Recently, tremendous improvements have been achieved in the precision of localization of single fluorescent molecules, allowing localization and tracking of biomolecules at the nm level. Since the behaviour of proteins and biological molecules is tightly influenced by the cell's environment, a growing number of microscopy techniques are moving from in vitro to live cell experiments. Looking at both...
Gallium Nitride based Light Emitting Diodes (LEDs) and Laser Diodes (LDs) are reliable devices which are emerging as the reference technology for light emission in the visible range of the electromagnetic spectrum. At the moment, a lot of effort is spent in order to achieve longer lifetimes for InGaN based green LDs, which could lead to the production of portable and highly miniaturized projection...
In this work a large effort has been invested in the development of new strategies for the fabrication of nanostructured plasmonic devices using colloidal lithography. Suitable for the creation of large-areas and extremely cheap nano-optical devices, this fabrication method provides an interesting alternative to more expensive lithographic techniques. Our preliminary results have been reported showing...
In the last years, the LIDAR technique has been successfully applied to the detection of the smoke plume emitted by wild fires. Up to now, the attention has been devoted to early detection of quite concentrated smoke plumes to reveal the first stage of fires as soon as possible. In this paper, it is shown how the LIDAR technique can also cope with widespread smoke, which can be the consequence of...
In this work we made a comparative study between the electrical performances of three different electron transport layers (ETLs), used to build inverted polymer solar cells (PSCs). Two different metal oxides are prepared with a solution process: the first one is zinc oxide, prepared by a solgel procedure dissolving zinc acetate and ethanolamine in the 2-methoxyethanol, the second one is titanium oxide,...
In this work an innovative approach for the characterization of biological growths on stone artifacts by means Raman spectroscopy is presented. In particular, a novel Raman probe (excitation wavelength 1064 nm) for performing temperature-controlled measurements was developed and tested on lichens preventing thermal alterations effects as well as speeding up the identification of the species. The possibility...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.