Thermal characterization of electrically injected thin-film InGaAsP microdisk lasers on Si

Abstract—We have performed a numerical and experimental analysis of the thermal behavior of electrically injected microdisk lasers that are defined in an InGaAsP-based thin film bonded on top of a silicon wafer. Both the turn-on as well as the pulsed-regime temperature evolution in the lasing region was simulated using the finite-element method. The simulation results are in good agreement with experimental data, which was extracted from the broadening of the time-averaged emission spectra. Lasing at room temperature was only possible in pulsed regime due to the high thermal resistance (10 K/mW). Some strategies to decrease the thermal resistance of the microdisk lasers are proposed and discussed. Index Terms—Heterogeneous integration, InGaAsP, integrated optics, microdisk laser, Si, thermal characterization

Medical ethics questions of COVID-19 vaccination in pregnant and lactating women in East Asia and Oceania

We aimed to investigate some of the medical ethics issues that characterize the COVID-19 vaccination phase in pregnancy and breast-feeding. A literature search was conducted using PubMed, Scopus, Web of Science, focusing mainly on the countries of East Asia and Oceania. Vaccination during pregnancy and breastfeeding appears to help protect babies from COVID-19 by enabling antibodies to pass from mother to baby. However, individual countries of the same continent may adopt conflicting policy positions. Not only that, indications on the type of vaccine sometimes vary, depending on whether a woman is pregnant or breastfeeding. In this review we have taken into considerationp the policy positions on pregnancy and lactation by country and type of Covid-19 vaccine in East Asia and Oceania. Ten out of the 18 countries considered (representing more than two thirds of the population of East Asia and Oceania) provide different vaccine indications for pregnant and breastfeeding women. Can this diversity of recommendations be seen as a form of optimal protection for women in these categories, or does it suggest that some countries have taken a defensive position to avoid compensation claims in the event of complications? Is it ethically correct to leave questions concerning informed consent open? Misin-formation during a health crisis leaves people without protection and with increased vaccine hesitancy, especially for vulnerable populations in hard-to-reach areas of East Asia and Oceania

Proof-of-concept demonstration of an all-optical de-multiplexer using III-V/SOI microdisk resonator fabricated in a CMOS pilot line

We present a proof-of-concept demonstration of all-optical de-multiplexing of a non-return-to zero 10Gbps data controlled by 2.5GHz clock in an ultra-small III-V-on-silicon microdisk fabricated in a CMOS pilot line

The Covid-19 pandemic - how well are we balancing health, freedom, and the economy?

The worsening healthcare emergency with the COVID-19 pandemic has demanded a prompt reaction from authorities to contain the damage related to the spread of the virus. Our aim is to provide a bioethical contribution, with a careful analysis about the balance of individual rights with those of the whole community. The protection of the right to health in the emergency phase, with the restriction of the right to work and other rights, can have long-term negative consequences on the economy, with fallout affecting funding for the healthcare system as well. The right to health in its community dimension can sometimes clash with the protection of the sacrosanct dignity of the individual. Choices to protect health may have social and economic repercussions that could undermine the stability of many national governments

Next Generation Cosmology: Constraints from the Euclid Galaxy Cluster Survey

We study the characteristics of the galaxy cluster samples expected from the European Space Agency's Euclid satellite and forecast constraints on cosmological parameters describing a variety of cosmological models. The method used in this paper, based on the Fisher Matrix approach, is the same one used to provide the constraints presented in the Euclid Red Book (Laureijs et al.2011). We describe the analytical approach to compute the selection function of the photometric and spectroscopic cluster surveys. Based on the photometric selection function, we forecast the constraints on a number of cosmological parameter sets corresponding to different extensions of the standard LambdaCDM model. The dynamical evolution of dark energy will be constrained to Delta w_0=0.03 and Delta w_a=0.2 with free curvature Omega_k, resulting in a (w_0,w_a) Figure of Merit (FoM) of 291. Including the Planck CMB covariance matrix improves the constraints to Delta w_0=0.02, Delta w_a=0.07 and a FoM=802. The amplitude of primordial non-Gaussianity, parametrised by f_NL, will be constrained to \Delta f_NL ~ 6.6 for the local shape scenario, from Euclid clusters alone. Using only Euclid clusters, the growth factor parameter \gamma, which signals deviations from GR, will be constrained to Delta \gamma=0.02, and the neutrino density parameter to Delta Omega_\nu=0.0013 (or Delta \sum m_\nu=0.01). We emphasise that knowledge of the observable--mass scaling relation will be crucial to constrain cosmological parameters from a cluster catalogue. The Euclid mission will have a clear advantage in this respect, thanks to its imaging and spectroscopic capabilities that will enable internal mass calibration from weak lensing and the dynamics of cluster galaxies. This information will be further complemented by wide-area multi-wavelength external cluster surveys that will already be available when Euclid flies. [Abridged]Comment: submitted to MNRA