ABSTRACT
The newly emerged 2019 coronavirus disease (COVID-19) has urged scientific and medical communities to focus on epidemiology, pathophysiology, and treatment of SARS-CoV-2. Indeed, little is known about the virus causing this severe acute respiratory syndrome pandemic, coronavirus (SARS-CoV-2). Data already collected on viruses belonging to the coronaviridae family are of interest to improve our knowledge rapidly on this pandemic. The current review aims at delivering insight into the fundamental advances inSARS-CoV-2 epidemiology, pathophysiology, life cycle, and treatment.
ABSTRACT
The optoelectronic properties of image sensors, among which are the photosensitivity and resolution, are key to the quality factors for imaging as well as spectrometry in Earth observation and scientific space exploration missions. Microlens arrays (MLAs) further improve state-of-the-art CMOS image sensors (CIS) by redirecting more photons into the photosensitive surface/volume of each pixel. This paper reports the design, deposition, optical characterization, and reliability assessment of such an MLA made from a UV-curable hybrid polymer and replicated on a packaged back-illuminated CIS having a pixel pitch of 15.5 µm. We find that such MLAs are highly stable to temperature variations, exposure to humidity, mechanical shocks and vibrations, as well as irradiation by gamma rays, while improving the parasitic light sensitivity by a factor of 1.8. Such MLAs can be applied on a large variety of image sensors, back-illuminated but mostly front-illuminated, with pixel pitches ranging from a few to several hundreds of micrometers, making them suitable for most specifications of the space industry.
ABSTRACT
Microlenses are an important functional element of a modern imaging device. Typically, they are fabricated from organic materials on top of individual pixels. Though they are widely used, they do exhibit a number of limitations. These are, but not limited to, thermal stability, radiation sensitivity, outgassing properties, additional topography, and difficulty in manufacturing asymmetrical, noncircular microlens designs using conventional manufacturing techniques. In this paper, we present a novel approach for the fabrication of microlenses. We report on the design, manufacturing, and characterization of microlenses fabricated from classical dielectric materials used in the manufacturing of CMOS semiconductor devices. These microlenses rely on a Fresnel optical design, provide functionality similar to the classical microlenses, and do not suffer from their limitations. We subjected these microlenses to several environmental reliability stress conditions, including pressure, temperature, humidity, and their variation. Moreover, we test their sensitivity to gamma rays and protons.
