Extremely uniform lasing wavelengths of InP microdisk lasers heterogeneously integrated on SOI

A standard deviation in lasing wavelength lower than 500pm is characterized on nominally identical and optically-pumped microdisk lasers, heterogeneously integrated on the same SOI circuit. This lasing wavelength uniformity is obtained using electron-beam lithography

Field Localization and Enhancement of Phase Locked Second and Third Harmonic Generation in Absorbing Semiconductor Cavities

We predict and experimentally observe the enhancement by three orders of magnitude of phase mismatched second and third harmonic generation in a GaAs cavity at 650nm and 433nm, respectively, well above the absorption edge. Phase locking between the pump and the harmonics changes the effective dispersion of the medium and inhibits absorption. Despite hostile conditions the harmonics become localized inside the cavity leading to relatively large conversion efficiencies. Field localization plays a pivotal role and ushers in a new class of semiconductor-based devices in the visible and UV ranges

Enhanced efficiency of the second harmonic inhomogeneous component in an opaque cavity

In this Letter, we experimentally demonstrate the enhancement of the inhomogeneous second harmonic conversion in the opaque region of a GaAs cavity with efficiencies of the order of 0.1% at 612nm, using 3 ps pump pulses having peak intensities of the order of 10MW=cm2. We show that the conversion efficiency of the inhomogeneous, phase-locked second harmonic component is a quadratic function of the cavity factor Q.Peer ReviewedPostprint (published version

Content and Face Validity of the Evaluation Tool of Health Information for Consumers (ETHIC): Getting Health Information Accessible to Patients and Citizens

Background: Health information concerns both individuals’ engagement and the way services and professionals provide information to facilitate consumers’ health decision making. Citizens’ and patients’ participation in the management of their own health is related to the availability of tools making health information accessible, thus promoting empowerment and making care more inclusive and fairer. A novel instrument was developed (Evaluation Tool of Health Information for Consumers—ETHIC) for assessing the formal quality of health information materials written in Italian language. This study reports ETHIC’s content and face validity. Methods: A convenience sample of 11 experts and 5 potential users was involved. The former were requested to evaluate relevance and exhaustiveness, the latter both readability and understandability of ETHIC. The Content Validity Index (CVI) was calculated for ETHIC’s sections and items; experts and potential users’ feedback were analyzed by the authors. Results: All sections and most items were evaluated as relevant. A new item was introduced. Potential users provided the researchers with comments that partly confirmed ETHIC’s clarity and understandability. Conclusions: Our findings strongly support the relevance of ETHIC’s sections and items. An updated version of the instrument matching exhaustivity, readability, and understandability criteria was obtained, which will be assessed for further steps of the validation process

Seasonality fluctuations recorded in fossil bivalves during the early Pleistocene: implications for climate change

Understanding the transformations of the climate system may help to predict and reduce the effects of global climate change. The geological record provides a unique archive that documents the long-term fluctuations of environmental variables, such as seasonal change. Here, we investigate how seasonal variation in seawater temperatures varied in the Mediterranean Sea during the early Pleistocene, approaching the Early-Middle Pleistocene Transition (EMPT) and the beginning of precession-driven Quaternary-style glacial–interglacial cycles. We performed whole-shell and sclerochemical stable isotope analyses (δ18O, δ13C) on bivalves, collected from the lower Pleistocene Arda River marine succession (northern Italy), after checking shell preservation. Our results indicate that seawater temperature seasonality was the main variable of climate change in the Mediterranean area during the early Pleistocene, with the Northern Hemisphere Glaciation (NHG) exerting a control on the Mediterranean climate. We show that strong seasonality (14.4–16.0 °C range) and low winter paleotemperatures (0.8–1.6 °C) were likely the triggers leading to the establishment of widespread populations of so called “northern guests” (i.e., cold water taxa) in the Mediterranean Sea around 1.80 Ma. The shells postdating the arrival of the “northern guests” record a return to lower seasonal variations and higher seawater paleotemperatures, with seasonality increasing again approaching the EMPT; the latter, however, is not associated with a corresponding cooling of mean seawater paleotemperatures, showing that the observed seasonality variation represents a clear signal of progressive climate change in the Mediterranean Sea

Heterogeneous integration and precise alignment of InP-based photonic crystal lasers to complementary metal-oxide semiconductor fabricated silicon-on-insulator wire waveguides

The integration of two-dimensional III-V InP-based photonic crystal and silicon wire waveguides is achieved through an accurate alignment of the two optical levels using mix-and-match deep ultraviolet (DUV)/electron beam lithography. The adhesively bonded structures exhibit an enhancement of light emission at frequencies where low group velocity modes of the photonic crystal line defect waveguides occur. Pulsed laser operation is obtained from these modes at room temperature under optical pumping. The laser light is coupled out of the Si waveguide via grating couplers directly to single mode fiber